#include <bits/stdc++.h>
using namespace std;
int a, b, t, f;
string s;
int main() {
  cin >> a >> b;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (i != a + 1 && s[i] != '0' && s[i] != '1' && s[i] != '2' &&
        s[i] != '3' && s[i] != '4' && s[i] != '5' && s[i] != '6' &&
        s[i] != '7' && s[i] != '8' && s[i] != '9') {
      cout << "No" << endl;
      return 0;
    } else if (s[a + 1] != '-') {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
}
