#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B, mul;
  cin >> A >> B;
  mul = A * B;
  if (A <= 1 || B <= 9 && A <= 9 || B <= 1) {
    cout << "A*B = " << mul << endl;
  } else {
    cout << "-1";
  }
  return 0;
}
