#include <bits/stdc++.h>
using namespace std;
const int maxN = 100005;
const int mod = (int)1e9 + 7;
char a[maxN];
int main() {
  int n, t;
  cin >> n >> t;
  if (n == 1) {
    if (t <= 9) {
      cout << t << endl;
    } else {
      cout << -1 << endl;
    }
    return 0;
  }
  int mod = 0;
  for (int i = 0; i < n - 1; ++i) {
    cout << 1;
    mod = (mod * 10 + 1) % t;
  }
  for (int dig = 0; dig < 10; ++dig) {
    if ((mod * 10 + dig) % t == 0) {
      cout << dig << endl;
      return 0;
    }
  }
  cout << -1 << endl;
}
