#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b;
  string s;
  cin >> a >> b >> s;
  bool ans = false;
  char c = s.at(a);
  if (c == '-') {
    for (int i = 0; i < s.size(); ++i) {
      if (0 <= s.at(i) <= 9) {
        ans = true;
      }
    }
  }
  if (ans == true)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
