#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, i = 0;
  cin >> a >> b;
  char s;
  while (cin >> s) {
    i++;
    if (i != a + 1) {
      if (s >= '0' && s <= '9') {
        cout << "Yes" << endl;
        return 0;
      } else {
        cout << "No" << endl;
        return 0;
      }
    }
    if (i == a + 1) {
      if (s != '-') {
        cout << "No" << endl;
        return 0;
      } else {
        cout << "Yes" << endl;
        return 0;
      }
    }
  }
}
