#include <bits/stdc++.h>
using namespace std;
int main() {
  int a = 0;
  int b = 0;
  cin >> a;
  cin >> b;
  if (a > 20)
    cout << "-1";
  else if (b > 20)
    cout << "-1";
  else
    cout << a << "x" << b << "=" << (a * b);
  return 0;
}
