mob.nt

module mob;

void main() {
  int A(int k, int delegate() x1, x2, x3, x4, x5) {
    int B() {
      k --;
      return A(k, &B, x1, x2, x3, x4);
    }
    if (k <= 0) return x4() + x5();
    else return B();
  }
  auto res = A(10, \-> 1, \-> -1, \-> -1, \-> 1, \-> 0);
  writeln "$res";
}