diff --git a/main.cpp b/main.cpp
index 712b5f0..a6c3d31 100644
--- a/main.cpp
+++ b/main.cpp
@@ -128,6 +128,8 @@ Moves serialize(const string &s) {
     int x, y;
     while (iss >> player >> x >> y) {
         if (player == "END") break;
+
+        // TODO: move this exceptions to runtime checks
         if (x >= result.x || y >= result.y) {
             string err = "Invalid move by: " + player + " (" + toString(x) + ", " + toString(y) + ")";
             throw invalid_argument(err);