#include <bits/stdc++.h>
int main(void) {
  int A;
  int B;
  printf("A?/n");
  scanf("%d", &A);
  printf("B?/n");
  scanf("%d", &B);
  if (1 <= A <= 9 && 1 <= B <= 9) {
    printf("A*B");
  } else if (10 <= A <= 20 || 10 <= B <= 20) {
    printf("-1/n");
  }
  return 0;
}
