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