#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string s;
  cin >> a >> b;
  cin >> s;
  bool flag = false;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] >= '0' && s[i] <= '9' && s[3] == '-') {
      flag = true;
    } else {
      flag = false;
      break;
    }
  }
  if (flag) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
