#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string S;
  cin >> a >> b;
  cin >> S;
  for (int i = 0; i < a + b + 1; i++) {
    if (i == a) {
      if (S[i] != '-') {
        cout << "No" << endl;
      }
    } else {
      if (std::isdigit(S[i]) == 0) {
        cout << "No" << endl;
      }
    }
  }
  cout << "Yes" << endl;
}
