#include <stdio.h>

int f2 (int x, int y) {
  int i, j, t[100][100];

  for (i = 1; i <= x; i++)
    t[i][1] = 0;
  for (j = 2; j <= y; j++)
    t[1][j] = 0;

  for (i = 2; i <= x; i++) 
    for (j = 2; j <= y; j++) 
      t[i][j] = t[i-1][j] + t[i][j-1] + i*j;
  return t[x][y];
}

int main() {
  int n, m;

  printf("Digite n e m: ");
  scanf("%d %d", &n, &m);
  printf("\nf(%d,%d) = %d\n", n, m, f2(n,m));
  return 0;
}