diff --git a/d07.lua b/d07.lua
new file mode 100644
index 0000000..f418bff
--- /dev/null
+++ b/d07.lua
@@ -0,0 +1,193 @@
+function get_arg(mem, pos, arg)
+    local param_mode = mem[pos] // (10 ^ (arg + 1)) % 10
+    if #mem < pos + arg then
+        print(string.format("Error: Opcode too short at end of memory: %d", pos))
+        os.exit(false)
+    end
+    local arg = mem[pos + arg]
+    if param_mode == 0 then
+        arg = arg + 1
+        if #mem < arg then
+            print(string.format("Error: Memory offset out of bounds: %d", arg))
+            os.exit(false)
+        end
+    end
+    return arg
+end
+
+function get_param(mem, pos, arg)
+    local param_mode = mem[pos] // (10 ^ (arg + 1)) % 10
+    local arg = get_arg(mem, pos, arg)
+    if param_mode == 0 then
+        return mem[arg]
+    end
+    return arg
+end
+
+function interpret(mem, state, input_func, output_func)
+    if not state.pos then
+        state.pos = 1
+    end
+
+    local pos = state.pos
+    while true do
+        if #mem < pos then
+            print(string.format("Instruction pointer ran off of memory"))
+            os.exit(false)
+        end
+
+        local opcode = mem[pos] % 100
+
+        if opcode == 1 then
+            mem[get_arg(mem, pos, 3)] = get_param(mem, pos, 1) + get_param(mem, pos, 2)
+            pos = pos + 4
+        elseif opcode == 2 then
+            mem[get_arg(mem, pos, 3)] = get_param(mem, pos, 1) * get_param(mem, pos, 2)
+            pos = pos + 4
+        elseif opcode == 3 then
+            local val = input_func()
+            if not val then
+                state.pos = pos
+                return true
+            end
+            mem[get_arg(mem, pos, 1)] = val
+            pos = pos + 2
+        elseif opcode == 4 then
+            output_func(get_param(mem, pos, 1))
+            pos = pos + 2
+        elseif opcode == 5 then
+            if get_param(mem, pos, 1) ~= 0 then
+                pos = get_param(mem, pos, 2) + 1
+            else
+                pos = pos + 3
+            end
+        elseif opcode == 6 then
+            if get_param(mem, pos, 1) == 0 then
+                pos = get_param(mem, pos, 2) + 1
+            else
+                pos = pos + 3
+            end
+        elseif opcode == 7 then
+            mem[get_arg(mem, pos, 3)] = get_param(mem, pos, 1) < get_param(mem, pos, 2) and 1 or 0
+            pos = pos + 4
+        elseif opcode == 8 then
+            mem[get_arg(mem, pos, 3)] = get_param(mem, pos, 1) == get_param(mem, pos, 2) and 1 or 0
+            pos = pos + 4
+        elseif opcode == 99 then
+            state.pos = pos
+            return false
+        else
+            print(string.format("Error: Invalid opcode %d at %d", opcode, pos - 1))
+            os.exit(false)
+        end
+    end
+end
+
+function input_stdin()
+    io.stdout:write("> ")
+    return io.stdin:read("n")
+end
+
+function output_stdout(val)
+    io.stdout:write(val)
+    io.stdout:write("\n")
+end
+
+function input_array(array)
+    function inner()
+        return table.remove(array, 1)
+    end
+    return inner
+end
+
+function output_array(array)
+    function inner(val)
+        table.insert(array, val)
+    end
+    return inner
+end
+
+file = io.open(arg[1])
+program = {}
+for num in string.gmatch(file:read(), "(-?%d+),?") do
+    table.insert(program, tonumber(num))
+end
+file:close()
+
+function get_signal(phase)
+    signal = 0
+    for i = 1, 5 do
+        memory = {table.unpack(program)}
+        output = {}
+        interpret(memory, {}, input_array({phase[i], signal}), output_array(output))
+        signal = output[1]
+    end
+    return signal
+end
+
+function get_signal_p2(phase)
+    machines = {}
+    for i = 1, 5 do
+        if i == 1 then
+            input = {}
+        else
+            input = machines[i - 1].output
+        end
+        table.insert(input, phase[i] + 5)
+        machines[i] = {mem={table.unpack(program)}, input=input, output={}}
+    end
+    machines[5].output = machines[1].input
+    table.insert(machines[1].input, 0)
+
+    while true do
+        done = true
+        for i = 1, 5 do
+            if interpret(machines[i].mem, machines[i], input_array(machines[i].input), output_array(machines[i].output)) then
+                done = false
+            end
+        end
+        if done then
+            break
+        end
+    end
+    return machines[5].output[1]
+end
+
+biggest = 0
+biggest_p2 = 0
+for i = 0, (5 ^ 5) - 1 do
+    phase = {
+        i // (5 ^ 4) % 5,
+        i // (5 ^ 3) % 5,
+        i // (5 ^ 2) % 5,
+        i // (5 ^ 1) % 5,
+        i // (5 ^ 0) % 5
+    }
+    count = {}
+    for _, x in ipairs(phase) do
+        if not count[x] then
+            count[x] = 0
+        end
+        count[x] = count[x] + 1
+    end
+    double = false
+    for _, x in pairs(count) do
+        if x > 1 then
+            double = true
+        end
+    end
+
+    if not double then
+        signal = get_signal(phase)
+        if signal > biggest then
+            biggest = signal
+        end
+        signal = get_signal_p2(phase)
+        if signal > biggest_p2 then
+            biggest_p2 = signal
+        end
+    end
+end
+
+print("Part 1:", biggest)
+print("Part 2:", biggest_p2)
diff --git a/d07_input.txt b/d07_input.txt
new file mode 100644
index 0000000..52d6c9b
--- /dev/null
+++ b/d07_input.txt
@@ -0,0 +1 @@
+3,8,1001,8,10,8,105,1,0,0,21,46,55,72,85,110,191,272,353,434,99999,3,9,1002,9,5,9,1001,9,2,9,102,3,9,9,101,2,9,9,102,4,9,9,4,9,99,3,9,102,5,9,9,4,9,99,3,9,1002,9,2,9,101,2,9,9,1002,9,2,9,4,9,99,3,9,1002,9,4,9,101,3,9,9,4,9,99,3,9,1002,9,3,9,101,5,9,9,1002,9,3,9,101,3,9,9,1002,9,5,9,4,9,99,3,9,1001,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,99,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,1,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,101,1,9,9,4,9,3,9,1001,9,1,9,4,9,3,9,101,2,9,9,4,9,99,3,9,1002,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,1,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,1,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,1,9,4,9,3,9,101,2,9,9,4,9,99,3,9,1001,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,101,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,1001,9,1,9,4,9,99,3,9,101,1,9,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,1002,9,2,9,4,9,3,9,102,2,9,9,4,9,3,9,102,2,9,9,4,9,3,9,1001,9,2,9,4,9,3,9,1001,9,2,9,4,9,99