diff --git a/2015/Day-01/Day01-1.cs b/2015/Day-01/Day01-1.cs
new file mode 100644
index 0000000..a149141
--- /dev/null
+++ b/2015/Day-01/Day01-1.cs
@@ -0,0 +1,35 @@
+// Input is one line so read it in as a string.
+string input = File.ReadAllText(@"input.txt").ToString();
+
+// Start on floor 0.
+int currentFloor = 0;
+
+// Counters for Part 2.
+int currentChar = 0;
+int part2 = 0;
+
+// Loop through each char in the string and go up/down as directed.
+foreach(char direction in input){
+    switch(direction){
+        case '(':
+            currentFloor++;
+            break;
+        case ')':
+            currentFloor--;
+            break;
+        default:
+            throw new InvalidDataException("Input did not match expected format!");
+    }
+
+    // Increment our counter.
+    currentChar++;
+
+    // If we are on -1 and part2 is still 0, update it.
+    if(currentFloor == -1 && part2 == 0){
+        part2 = currentChar;
+    }
+}
+
+// Print out the answers.
+Console.WriteLine("Part 1: " + currentFloor);
+Console.WriteLine("Part 2: " + part2);