diff --git a/2020/days/day13.cpp b/2020/days/day13.cpp
new file mode 100644
index 0000000..576af53
--- /dev/null
+++ b/2020/days/day13.cpp
@@ -0,0 +1,106 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2020 Gnarwhal
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files(the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ *******************************************************************************/
+
+#include <vector>
+#include <string>
+#include <iostream>
+#include <fstream>
+
+#include "../misc/types.hpp"
+#include "../misc/print.hpp"
+
+struct Pair{ u64 id; usize index; };
+
+auto find_least(u64 new_base, u64 new_loop, u64 req_base, u64 req_loop, u64 iter) -> u64 {
+	while ((new_base + ++iter * new_loop - req_base) % req_loop != 0);
+	return new_base + iter * new_loop;
+}
+
+auto day13() -> void {
+	auto ready = usize(0);
+	auto buses = std::vector<Pair>();
+	{
+		auto line = std::string();
+		auto file = std::ifstream("inputs/day13.input");
+		getline(file, line);
+		ready = std::stoi(line);
+		getline(file, line);
+		auto start = usize(0);
+		auto end   = usize(0);
+		auto index = usize(0);
+		auto id    = std::string();
+		while ((end = line.find(',', start)) != std::string::npos) {
+			id = line.substr(start, end - start);
+			if (id != "x") {
+				buses.push_back({ u64(std::stoi(line.substr(start, end - start))), index });
+			}
+			start = end + 1;
+			++index;
+		}
+		end = line.size();
+		id = line.substr(start, end - start);
+		if (id != "x") {
+			buses.push_back({ u64(std::stoi(line.substr(start, end - start))), index });
+		}
+	}
+	
+	auto id      = buses[0].id;
+	auto minutes = buses[0].id - (ready % buses[0].id);
+	for (auto i = usize(1); i < buses.size(); ++i) {
+		auto local_minutes = buses[i].id - (ready % buses[i].id);
+		if (local_minutes < minutes) {
+			id      = buses[i].id;
+			minutes = local_minutes;
+		}
+	}
+	print((id * minutes));
+
+	auto req_base = usize(0);
+	auto req_loop = usize(1);
+	for (auto i = usize(1); i < buses.size(); ++i) {
+		auto base_loop = usize(-1);
+		while ((++base_loop * buses[0].id + buses[i].index) % buses[i].id != 0);
+
+		auto rep_loop = usize(0);
+		while ((++rep_loop * buses[0].id) % buses[i].id != 0);
+
+		req_base = find_least(base_loop, rep_loop, req_base, req_loop, -1);
+		if (i < buses.size() - 1) {
+			req_loop = find_least(0, rep_loop, 0, req_loop, 0);
+		}
+		/*
+		required_base (rqb), required_loop (rql)
+
+		base_loop (bl), repeat_loop (rl)
+
+		rqb + a0 * rql = bl + a1 * rl < minimize and store in required loop
+		a0 = (bl + a1 * rl - rqb) / rql
+
+		b0 * rql = b1 * rl < minimize and store in required loop
+		*/
+	}
+	print((req_base * buses[0].id));
+}
diff --git a/2020/days/day14.cpp b/2020/days/day14.cpp
new file mode 100644
index 0000000..a38fbd6
--- /dev/null
+++ b/2020/days/day14.cpp
@@ -0,0 +1,112 @@
+/*******************************************************************************
+ *
+ * Copyright (c) 2020 Gnarwhal
+ *
+ * -----------------------------------------------------------------------------
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files(the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ *******************************************************************************/
+
+#include <vector>
+#include <map>
+#include <string>
+#include <bitset>
+#include <iostream>
+#include <fstream>
+
+#include "../misc/types.hpp"
+#include "../misc/print.hpp"
+
+struct Op{ u8 op; u64 num1; u64 num2; };
+
+auto set_memory(std::map<u64, u64> & map, u64 addr, const std::vector<bool> & maskX, usize index, u64 value) -> void {
+	while (++index < maskX.size() && !maskX[index]);
+	if (index == maskX.size()) {
+		map.insert_or_assign(addr, value);
+	} else {
+		set_memory(map, addr, maskX, index, value);
+		set_memory(map, addr ^ (u64(1) << (maskX.size() - index - 1)), maskX, index, value);
+	}
+}
+
+auto day14() -> void {
+	auto ops = std::vector<Op>();
+	{
+		auto line = std::string();
+		auto file = std::ifstream("inputs/day14.input");
+		while (getline(file, line)) {
+			if (line.find("mask") != std::string::npos) {
+				auto mask0 = u64(-1);
+				auto mask1 = u64( 0);
+				for (auto i = usize(7); i < line.size(); ++i) {
+					if (line[i] == '0') {
+						mask0 ^= (u64(1) << (42 - i));
+					} else if (line[i] == '1') {
+						mask1 ^= (u64(1) << (42 - i));
+					}
+				}
+				ops.push_back({ 0, mask0, mask1 });
+			} else {
+				auto value = line.find("=") + 2;
+				ops.push_back({
+					1,
+					u64(std::stoll(line.substr(4, line.find("]") - 4))),
+					u64(std::stoll(line.substr(value, line.size() - value)))
+				});
+			}
+		}
+	}
+	auto mask0  = u64(-1);
+	auto mask1  = u64( 0);
+	auto memory = std::map<u64, u64>();
+	for (auto op : ops) {
+		if (op.op == 0) {
+			mask0 = op.num1;
+			mask1 = op.num2;
+		} else {
+			memory.insert_or_assign(op.num1, (op.num2 & mask0) | mask1);
+		}
+	}
+	auto sum = u64(0);
+	for(auto mem : memory) {
+		sum += mem.second;
+	}
+	print(sum);
+
+	mask1  = u64(0);
+	memory = std::map<u64, u64>();
+	auto maskX = std::vector<bool>(36);
+	for (auto op : ops) {
+		if (op.op == 0) {
+			mask1 = op.num2;
+			for (auto i = usize(0); i < maskX.size(); ++i) {
+				auto bit = u64(1) << u64(35 - i);
+				maskX[i] = (op.num1 & bit) && !(op.num2 & bit);
+			}
+		} else {
+			set_memory(memory, op.num1 | mask1, maskX, -1, op.num2);
+		}
+	}
+	sum = u64(0);
+	for(auto mem : memory) {
+		sum += mem.second;
+	}
+	print(sum);
+}