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