#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  bool flg = false;
  if (s[a] == '-') {
    for (int i = 0; i < a + b + 1; i++) {
      int num = (int)(s[i] - '0');
      if (0 <= num && num <= 9) {
        flg = true;
      }
    }
  }
  if (flg) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
