diff --git a/2019/src/day07.cpp b/2019/src/day07.cpp
index 603b222..07bb868 100644
--- a/2019/src/day07.cpp
+++ b/2019/src/day07.cpp
@@ -1,8 +1,31 @@
 #include <iostream>
 #include "days.hpp"
+#include "utils.hpp"
+
+namespace  {
+    int simulate(const std::vector<int>& program, const std::vector<int> phases) {
+        int state = 0;
+        for (int phase : phases) {
+            auto copy = program;
+            auto result = aoc2019::run_intcode(copy, { phase, state });
+            state = result.front();
+        }
+
+        return state;
+    }
+}
 
 void aoc2019::day07_part1(std::istream &input, std::ostream &output) {
-	output << "Not implemented\n";
+    const auto program = aoc2019::read_intcode(input);
+    std::vector<int> phases{0, 1, 2, 3, 4};
+
+    int best = 0;
+
+    do {
+        best = std::max(simulate(program, phases), best);
+    } while (std::next_permutation(phases.begin(), phases.end()));
+
+	output << best << std::endl;
 }
 
 void aoc2019::day07_part2(std::istream &input, std::ostream &output) {
diff --git a/2019/tests/samples/07-1-1.in b/2019/tests/samples/07-1-1.in
new file mode 100644
index 0000000..e626457
--- /dev/null
+++ b/2019/tests/samples/07-1-1.in
@@ -0,0 +1 @@
+3,15,3,16,1002,16,10,16,1,16,15,15,4,15,99,0,0
diff --git a/2019/tests/samples/07-1-1.out b/2019/tests/samples/07-1-1.out
new file mode 100644
index 0000000..d977160
--- /dev/null
+++ b/2019/tests/samples/07-1-1.out
@@ -0,0 +1 @@
+43210
diff --git a/2019/tests/samples/07-1-2.in b/2019/tests/samples/07-1-2.in
new file mode 100644
index 0000000..99ab27e
--- /dev/null
+++ b/2019/tests/samples/07-1-2.in
@@ -0,0 +1,2 @@
+3,23,3,24,1002,24,10,24,1002,23,-1,23,
+101,5,23,23,1,24,23,23,4,23,99,0,0
diff --git a/2019/tests/samples/07-1-2.out b/2019/tests/samples/07-1-2.out
new file mode 100644
index 0000000..67c0579
--- /dev/null
+++ b/2019/tests/samples/07-1-2.out
@@ -0,0 +1 @@
+54321
diff --git a/2019/tests/samples/07-1-3.in b/2019/tests/samples/07-1-3.in
new file mode 100644
index 0000000..6f8a3b2
--- /dev/null
+++ b/2019/tests/samples/07-1-3.in
@@ -0,0 +1,2 @@
+3,31,3,32,1002,32,10,32,1001,31,-2,31,1007,31,0,33,
+1002,33,7,33,1,33,31,31,1,32,31,31,4,31,99,0,0,0
diff --git a/2019/tests/samples/07-1-3.out b/2019/tests/samples/07-1-3.out
new file mode 100644
index 0000000..8c1ca06
--- /dev/null
+++ b/2019/tests/samples/07-1-3.out
@@ -0,0 +1 @@
+65210