message: Update handshakes-that-dont-cross.cpp
diff: @@ -25,7 +25,7 @@ private:
  return pow(x, m - 2, m);
  }
  - int pow(uint64_t a, int b, int m) {
  + int pow(uint64_t a, int b, int m) { // O(logMOD) = O(1)
  a %= m;
  uint64_t result = 1;
  while (b) {
  