#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  for (int i = 0; i < S.size(); i++) {
    if (i == A) {
      if (S[i] != '-') {
        cout << "No" << endl;
        return 0;
      }
    } else {
      if (!(S[i] >= '0' && S[i] <= '9')) {
        cout << "No" << endl;
        return 0;
      }
    }
    cout << "Yes" << endl;
  }
}
