#include <bits/stdc++.h>
int main() {
  int a, b, c;
  printf("please input the first integer:");
  if (a > 9 && a < 1)
    printf("-1");
  else
    scanf("%d", &a);
  printf("please input the second integer:");
  if (b > 9 && b < 1)
    printf("-1");
  else
    scanf("%d", &b);
  c = a * b;
  printf("%d\n", c);
  return 0;
}
