title: Number Rectangles Nm Grid
signature: function numberRectanglesNmGrid($n, $m) {
source_py: def number_rectangles_nm_grid(n, m):
      return ((((m * n) * (n + 1)) * (m + 1)) // 4)
source_cpp: int number_rectangles_nm_grid(int n, int m) {
    return ( m * n * ( n + 1 ) * ( m + 1 ) ) / 4;
  }