diff --git a/06/CMakeLists.txt b/06/CMakeLists.txt
new file mode 100644
index 0000000..a1778f8
--- /dev/null
+++ b/06/CMakeLists.txt
@@ -0,0 +1,22 @@
+cmake_minimum_required(VERSION 3.10)
+set(CMAKE_CXX_STANDARD 14)
+set(CMAKE_CXX_STANDARD_REQUIRED True)
+set(CMAKE_EXPORT_COMPILE_COMMANDS ON)
+enable_language(CXX)
+
+project(AoC05)
+
+if(APPLE)
+    include_directories(/usr/local/include)
+    link_directories(/usr/local/lib)
+endif()
+
+if(WIN32)
+	add_executable(${CMAKE_PROJECT_NAME} WIN32)
+else()
+	add_executable(${CMAKE_PROJECT_NAME})
+endif()
+
+target_sources(${CMAKE_PROJECT_NAME}
+	PRIVATE main.cpp
+	)
diff --git a/06/input b/06/input
new file mode 100644
index 0000000..1907feb
--- /dev/null
+++ b/06/input
@@ -0,0 +1 @@
+3,4,3,1,2,1,5,1,1,1,1,4,1,2,1,1,2,1,1,1,3,4,4,4,1,3,2,1,3,4,1,1,3,4,2,5,5,3,3,3,5,1,4,1,2,3,1,1,1,4,1,4,1,5,3,3,1,4,1,5,1,2,2,1,1,5,5,2,5,1,1,1,1,3,1,4,1,1,1,4,1,1,1,5,2,3,5,3,4,1,1,1,1,1,2,2,1,1,1,1,1,1,5,5,1,3,3,1,2,1,3,1,5,1,1,4,1,1,2,4,1,5,1,1,3,3,3,4,2,4,1,1,5,1,1,1,1,4,4,1,1,1,3,1,1,2,1,3,1,1,1,1,5,3,3,2,2,1,4,3,3,2,1,3,3,1,2,5,1,3,5,2,2,1,1,1,1,5,1,2,1,1,3,5,4,2,3,1,1,1,4,1,3,2,1,5,4,5,1,4,5,1,3,3,5,1,2,1,1,3,3,1,5,3,1,1,1,3,2,5,5,1,1,4,2,1,2,1,1,5,5,1,4,1,1,3,1,5,2,5,3,1,5,2,2,1,1,5,1,5,1,2,1,3,1,1,1,2,3,2,1,4,1,1,1,1,5,4,1,4,5,1,4,3,4,1,1,1,1,2,5,4,1,1,3,1,2,1,1,2,1,1,1,2,1,1,1,1,1,4
diff --git a/06/main.cpp b/06/main.cpp
new file mode 100644
index 0000000..4752493
--- /dev/null
+++ b/06/main.cpp
@@ -0,0 +1,66 @@
+#include <fstream>
+#include <iostream>
+#include <sstream>
+#include <vector>
+
+std::vector<int> getFish(const std::string &file_name) {
+    std::vector<int> fish;
+
+    std::ifstream file(file_name);
+    std::string str;
+    std::getline(file, str);
+    int tmp{};
+    char tmp_char{};
+    std::stringstream ss(str);
+    while (ss >> tmp) {
+        fish.push_back(tmp);
+        ss >> tmp_char;
+    }
+    return fish;
+}
+
+uint64_t computeFish(std::vector<int> fish, int lifecycle, int young_addition,
+                     int days) {
+    // index of bucket = days until reproduction
+    std::vector<uint64_t> fish_buckets{};
+    for (int i = 0; i < lifecycle + young_addition; i++) {
+        fish_buckets.push_back(0);
+    }
+    for (auto &f : fish) {
+        fish_buckets[f] += 1;
+    }
+    for (int i = 0; i < days; i++) {
+        auto new_fish = fish_buckets[0];
+        for (int j = 1; j < fish_buckets.size(); j++) {
+            fish_buckets[j - 1] = fish_buckets[j];
+        }
+        fish_buckets[lifecycle - 1] += new_fish;
+        fish_buckets.back() = new_fish;
+    }
+    uint64_t population = 0;
+    for (auto &f : fish_buckets) {
+        population += f;
+    }
+    return population;
+}
+
+uint64_t part1(const std::vector<int> &fish) {
+    return computeFish(fish, 7, 2, 80);
+}
+
+uint64_t part2(const std::vector<int> &fish) {
+    return computeFish(fish, 7, 2, 256);
+}
+
+int main(int argc, char **argv) {
+    if (argc < 2) {
+        std::cerr << "You must provide input file!" << std::endl;
+        return 1;
+    }
+    auto fish = getFish(argv[1]);
+    std::cout << "The number of fish after 80 days is \033[91;1m" << part1(fish)
+              << "\033[0m." << std::endl;
+    std::cout << "The number of fish after 256 days is \033[91;1m"
+              << part2(fish) << "\033[0m." << std::endl;
+    return 0;
+}