diff --git a/CMakeLists.txt b/CMakeLists.txt
index b9361eb..093b595 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -15,27 +15,31 @@ else()
 endif()
 
 add_subdirectory(lib)
+add_subdirectory(intcode)
+
+add_executable(day01 day01.cpp)
+target_link_libraries(day01 aocpp)
 
 add_executable(day02 day02.cpp)
-target_link_libraries(day02 intcode)
+target_link_libraries(day02 aocpp intcode)
 
 add_executable(day05 day05.cpp)
-target_link_libraries(day05 intcode)
+target_link_libraries(day05 aocpp intcode)
 
 add_executable(day07 day07.cpp)
-target_link_libraries(day07 intcode)
+target_link_libraries(day07 aocpp intcode)
 
 add_executable(day09 day09.cpp)
-target_link_libraries(day09 intcode)
+target_link_libraries(day09 aocpp intcode)
 
 add_executable(day11 day11.cpp)
-target_link_libraries(day11 intcode)
+target_link_libraries(day11 aocpp intcode)
 
 add_executable(day13 day13.cpp)
-target_link_libraries(day13 intcode)
+target_link_libraries(day13 aocpp intcode)
 
 add_executable(day15 day15.cpp)
-target_link_libraries(day15 intcode)
+target_link_libraries(day15 aocpp intcode)
 
 add_executable(day23 day23.cpp)
-target_link_libraries(day23 intcode)
+target_link_libraries(day23 aocpp intcode)
diff --git a/day01.cpp b/day01.cpp
new file mode 100644
index 0000000..624630d
--- /dev/null
+++ b/day01.cpp
@@ -0,0 +1,33 @@
+#include <algorithm>
+#include <numeric>
+#include <cstdlib>
+#include <cstdint>
+#include <iostream>
+#include <fstream>
+#include <iterator>
+#include <vector>
+#include <string>
+
+#include <aocpp/Startup.hpp>
+
+auto main(int argc, char** argv) -> int {
+  auto fin = aocpp::Startup(argc, argv);
+  std::vector<std::int64_t> input;
+  std::copy(std::istream_iterator<std::int64_t>{fin},
+            std::istream_iterator<std::int64_t>{},
+            std::back_inserter(input));
+
+  auto fuel = [](std::int64_t& x) { return x=x/3-2; };
+
+  std::int64_t part1 = 0;
+  std::int64_t part2 = 0;
+
+  for (auto x : input) {
+    part1 += fuel(x);
+    for (; x > 0; fuel(x)) {
+      part2 += x;
+    }
+  }
+  std::cout << "Part 1: " << part1 << std::endl;
+  std::cout << "Part 2: " << part2 << std::endl;
+}
diff --git a/day02.cpp b/day02.cpp
index cacfcca..eca052f 100644
--- a/day02.cpp
+++ b/day02.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <utility>
 
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
 
 using namespace intcode;
@@ -17,7 +18,8 @@ auto Compute(Machine machine, ValueType x, ValueType y) {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
 
   std::cout << "Part 1: " << Compute(machine, 12, 2) << std::endl;
 
diff --git a/day05.cpp b/day05.cpp
index 6885cfc..19609b1 100644
--- a/day05.cpp
+++ b/day05.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <utility>
 
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
 using namespace intcode;
 
@@ -17,7 +18,8 @@ auto Compute(Machine machine, ValueType d) -> ValueType {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
   std::cout << "Part 1: " << Compute(machine, 1) << std::endl;
   std::cout << "Part 2: " << Compute(std::move(machine), 5) << std::endl;
 }
diff --git a/day07.cpp b/day07.cpp
index 59e39a4..2b2c3b1 100644
--- a/day07.cpp
+++ b/day07.cpp
@@ -5,16 +5,19 @@
 #include <utility>
 #include <vector>
 
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
 using namespace intcode;
 
 namespace {
 
 template <class R> auto Controller(Machine machine, R const &params) {
+  auto& i = std::get<Input>(Step(machine)).input;
   std::vector<Machine> amps;
+  amps.reserve(params.size());
   for (auto p : params) {
+    i = p;
     amps.push_back(machine);
-    StepInput(amps.back(), p);
   }
   return amps;
 }
@@ -59,7 +62,8 @@ auto optimize(Machine machine, std::vector<ValueType> params, F f) {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
   std::cout << "Part 1: " << optimize(machine,            {0, 1, 2, 3, 4}, compute1) << std::endl;
   std::cout << "Part 2: " << optimize(std::move(machine), {5, 6, 7, 8, 9}, compute2) << std::endl;
 }
diff --git a/day09.cpp b/day09.cpp
index 0823756..f59db69 100644
--- a/day09.cpp
+++ b/day09.cpp
@@ -1,6 +1,7 @@
 #include <iostream>
 #include <utility>
 
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
 using namespace intcode;
 
@@ -17,7 +18,8 @@ auto Compute(Machine machine, ValueType d) -> ValueType {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
   std::cout << "Part 1: " << Compute(machine, 1) << std::endl;
   std::cout << "Part 2: " << Compute(std::move(machine), 2) << std::endl;
 }
diff --git a/day11.cpp b/day11.cpp
index 8db1ad2..2455bad 100644
--- a/day11.cpp
+++ b/day11.cpp
@@ -3,8 +3,10 @@
 #include <tuple>
 #include <map>
 
+#include <aocpp/Startup.hpp>
+#include <aocpp/Coord.hpp>
 #include <intcode/intcode.hpp>
-#include <intcode/Coord.hpp>
+using namespace aocpp;
 using namespace intcode;
 
 namespace {
@@ -36,7 +38,8 @@ auto Compute(Machine machine, ValueType start)
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
   std::cout << "Part 1: " << Compute(machine, 0).size() << "\nPart 2\n";
   Draw(std::cout, Compute(std::move(machine), 1));
 }
diff --git a/day13.cpp b/day13.cpp
index e1b5d3d..b90f301 100644
--- a/day13.cpp
+++ b/day13.cpp
@@ -4,8 +4,10 @@
 #include <tuple>
 #include <set>
 
+#include <aocpp/Startup.hpp>
+#include <aocpp/Coord.hpp>
 #include <intcode/intcode.hpp>
-#include <intcode/Coord.hpp>
+using namespace aocpp;
 using namespace intcode;
 
 namespace {
@@ -58,7 +60,8 @@ auto Compute2(Machine machine) {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machine = Startup(argc, argv);
+  auto fin = aocpp::Startup(argc, argv);
+  auto machine = Machine{ParseStream(fin)};
   std::cout << "Part 1: " << Compute1(machine) << std::endl;
   std::cout << "Part 2: " << Compute2(std::move(machine)) << std::endl;
 }
diff --git a/day15.cpp b/day15.cpp
index eac9837..9f290bc 100644
--- a/day15.cpp
+++ b/day15.cpp
@@ -6,8 +6,10 @@
 #include <utility>
 #include <vector>
 
+#include <aocpp/Coord.hpp>
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
-#include <intcode/Coord.hpp>
+using namespace aocpp;
 using namespace intcode;
 
 namespace {
@@ -89,7 +91,8 @@ auto Compute(std::map<Coord, ValueType> world) -> std::pair<int, int> {
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto [p1,p2] = Compute(Explore(Startup(argc, argv)));
+  auto fin = aocpp::Startup(argc, argv);
+  auto [p1,p2] = Compute(Explore(Machine{ParseStream(fin)}));
   std::cout << "Part 1: " << p1 << std::endl;
   std::cout << "Part 2: " << p2 << std::endl;
 }
diff --git a/day23.cpp b/day23.cpp
index a1f7eb5..a952965 100644
--- a/day23.cpp
+++ b/day23.cpp
@@ -2,12 +2,11 @@
 #include <deque>
 #include <iostream>
 #include <stdexcept>
-#include <tuple>
 #include <utility>
 #include <variant>
 #include <vector>
-#include <fstream>
 
+#include <aocpp/Startup.hpp>
 #include <intcode/intcode.hpp>
 using namespace intcode;
 
@@ -19,10 +18,13 @@ using Ethernet = std::deque<Packet>;
 
 auto BuildNetwork(Machine m) -> std::vector<Machine> {
   std::vector<Machine> machines;
+  machines.reserve(50);
+
   auto& i = std::get<Input>(Step(m)).input;
   for (i = 0; i < 50; i++) {
     machines.push_back(m);
   }
+
   return machines;
 }
 
@@ -55,7 +57,8 @@ auto Interact(Ethernet & ethernet, Machine & m, std::optional<Payload> p) -> voi
 } // namespace
 
 auto main(int argc, char** argv) -> int {
-  auto machines = BuildNetwork(Startup(argc, argv));
+  auto fin = aocpp::Startup(argc, argv);
+  auto machines = BuildNetwork(Machine{ParseStream(fin)});
   auto ethernet = Ethernet{};
 
   std::optional<ValueType> part1;
diff --git a/intcode/CMakeLists.txt b/intcode/CMakeLists.txt
new file mode 100644
index 0000000..e10e3fc
--- /dev/null
+++ b/intcode/CMakeLists.txt
@@ -0,0 +1,2 @@
+add_library(intcode src/Parser.cpp src/Interpreter.cpp src/Machine.cpp)
+target_include_directories(intcode PUBLIC include)
diff --git a/lib/include/Overload.hpp b/intcode/include/Overload.hpp
similarity index 100%
rename from lib/include/Overload.hpp
rename to intcode/include/Overload.hpp
diff --git a/lib/include/intcode/Interpreter.hpp b/intcode/include/intcode/Interpreter.hpp
similarity index 100%
rename from lib/include/intcode/Interpreter.hpp
rename to intcode/include/intcode/Interpreter.hpp
diff --git a/lib/include/intcode/Machine.hpp b/intcode/include/intcode/Machine.hpp
similarity index 82%
rename from lib/include/intcode/Machine.hpp
rename to intcode/include/intcode/Machine.hpp
index 2066f98..7cd100a 100644
--- a/lib/include/intcode/Machine.hpp
+++ b/intcode/include/intcode/Machine.hpp
@@ -4,6 +4,7 @@
 #include <cstddef>
 #include <unordered_map>
 #include <vector>
+#include <iostream>
 
 namespace intcode {
 
@@ -17,7 +18,10 @@ class Machine {
 
 public:
   Machine();
-  explicit Machine(std::vector<ValueType> ram);
+
+  /// Initialize a new machine with a given program starting
+  /// execution and program counter 0.
+  explicit Machine(std::vector<ValueType> program);
 
   /// Access memory at absolute address
   /// @param address
diff --git a/lib/include/intcode/Parser.hpp b/intcode/include/intcode/Parser.hpp
similarity index 100%
rename from lib/include/intcode/Parser.hpp
rename to intcode/include/intcode/Parser.hpp
diff --git a/lib/include/intcode/intcode.hpp b/intcode/include/intcode/intcode.hpp
similarity index 85%
rename from lib/include/intcode/intcode.hpp
rename to intcode/include/intcode/intcode.hpp
index 44cd87f..fb11a8f 100644
--- a/lib/include/intcode/intcode.hpp
+++ b/intcode/include/intcode/intcode.hpp
@@ -4,7 +4,6 @@
 #include <intcode/Interpreter.hpp>
 #include <intcode/Machine.hpp>
 #include <intcode/Parser.hpp>
-#include <intcode/Startup.hpp>
 #include <Overload.hpp>
 
 #endif
diff --git a/lib/src/Interpreter.cpp b/intcode/src/Interpreter.cpp
similarity index 100%
rename from lib/src/Interpreter.cpp
rename to intcode/src/Interpreter.cpp
diff --git a/lib/src/Machine.cpp b/intcode/src/Machine.cpp
similarity index 83%
rename from lib/src/Machine.cpp
rename to intcode/src/Machine.cpp
index e7737cf..9e2f56f 100644
--- a/lib/src/Machine.cpp
+++ b/intcode/src/Machine.cpp
@@ -4,8 +4,8 @@ namespace intcode {
 
 Machine::Machine() : rom_{}, ram_{}, pc_{0}, base_{0} {}
 
-Machine::Machine(std::vector<ValueType> ram)
-    : rom_{ram}, ram_{}, pc_{0}, base_{0} {}
+Machine::Machine(std::vector<ValueType> program)
+    : rom_{program}, ram_{}, pc_{0}, base_{0} {}
 
 auto Machine::At(std::size_t i) -> ValueType & {
   return i < rom_.size() ? rom_[i] : ram_[i];
diff --git a/lib/src/Parser.cpp b/intcode/src/Parser.cpp
similarity index 100%
rename from lib/src/Parser.cpp
rename to intcode/src/Parser.cpp
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index 93ec6be..6fb1e73 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -1,2 +1,2 @@
-add_library(intcode src/Coord.cpp src/Parser.cpp src/Interpreter.cpp src/Machine.cpp src/Startup.cpp)
-target_include_directories(intcode PUBLIC include)
+add_library(aocpp src/Startup.cpp src/Coord.cpp)
+target_include_directories(aocpp PUBLIC include)
\ No newline at end of file
diff --git a/lib/include/intcode/Coord.hpp b/lib/include/aocpp/Coord.hpp
similarity index 80%
rename from lib/include/intcode/Coord.hpp
rename to lib/include/aocpp/Coord.hpp
index 712b9be..0eb4bf4 100644
--- a/lib/include/intcode/Coord.hpp
+++ b/lib/include/aocpp/Coord.hpp
@@ -1,14 +1,12 @@
-#ifndef INTCODE_COORD_HPP_
-#define INTCODE_COORD_HPP_
+#ifndef AOCPP_COORD_HPP_
+#define AOCPP_COORD_HPP_
 
 #include <functional>
 #include <map>
 #include <ostream>
 #include <tuple>
 
-#include <intcode/Machine.hpp>
-
-namespace intcode {
+namespace aocpp {
 
 /// Cartesian coordinate
 ///
@@ -19,7 +17,7 @@ struct Coord {
 };
 
 
-auto Draw(std::ostream & out, std::map<Coord, ValueType> image) -> void;
+auto Draw(std::ostream & out, std::map<Coord, std::int64_t> image) -> void;
 
 /// Move one unit up
 auto Up(Coord) -> Coord;
@@ -60,9 +58,9 @@ auto operator<<(std::ostream &, Coord) -> std::ostream &;
 } // namespace
 
 template<>
-struct std::hash<intcode::Coord>
+struct std::hash<aocpp::Coord>
 {
-  auto operator()(intcode::Coord const& c) const noexcept -> std::size_t {
+  auto operator()(aocpp::Coord const& c) const noexcept -> std::size_t {
     std::hash<std::int64_t> h;
     return h(c.x) ^ h(c.y);
   }
diff --git a/lib/include/aocpp/Startup.hpp b/lib/include/aocpp/Startup.hpp
new file mode 100644
index 0000000..c527c24
--- /dev/null
+++ b/lib/include/aocpp/Startup.hpp
@@ -0,0 +1,10 @@
+#ifndef AOCPP_STARTUP_HPP_
+#define AOCPP_STARTUP_HPP_
+
+#include <fstream>
+
+namespace aocpp {
+auto Startup(int argc, char ** argv) -> std::ifstream;
+}
+
+#endif
diff --git a/lib/src/Coord.cpp b/lib/src/Coord.cpp
index 9ba63f6..992a248 100644
--- a/lib/src/Coord.cpp
+++ b/lib/src/Coord.cpp
@@ -1,9 +1,9 @@
-#include <intcode/Coord.hpp>
+#include <aocpp/Coord.hpp>
 
-namespace intcode {
+namespace aocpp {
 
-auto Draw(std::ostream & out, std::map<Coord, ValueType> image) -> void {
-  ValueType minX = 0, maxX = 0, minY = 0, maxY = 0;
+auto Draw(std::ostream & out, std::map<Coord, std::int64_t> image) -> void {
+  std::int64_t minX = 0, maxX = 0, minY = 0, maxY = 0;
   for (auto&& [k, _] : image) {
     auto [x,y] = k;
     minX = std::min(minX, x);
@@ -11,8 +11,8 @@ auto Draw(std::ostream & out, std::map<Coord, ValueType> image) -> void {
     minY = std::min(minY, y);
     maxY = std::max(maxY, y);
   }
-  for (ValueType y = minY; y <= maxY; y++) {
-    for (ValueType x = minX; x <= maxX; x++) {
+  for (std::int64_t y = minY; y <= maxY; y++) {
+    for (std::int64_t x = minX; x <= maxX; x++) {
       auto it = image.find({x,y});
       if (image.end() == it) {
         out << "░";
diff --git a/lib/src/Startup.cpp b/lib/src/Startup.cpp
new file mode 100644
index 0000000..c12197c
--- /dev/null
+++ b/lib/src/Startup.cpp
@@ -0,0 +1,17 @@
+#include <aocpp/Startup.hpp>
+
+#include <cstdlib>
+#include <iostream>
+#include <fstream>
+
+namespace aocpp {
+
+auto Startup(int argc, char ** argv) -> std::ifstream {
+  if (argc != 2) {
+    std::cerr << "Expected input file argument\n";
+    exit(EXIT_FAILURE);
+  }
+  return std::ifstream{argv[1]};
+}
+
+}