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