#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b, st;
  cin >> a >> b;
  st = a + 1;
  string s;
  cin >> s;
  if (s[a] == '-') {
    int flag = 0;
    for (int i = st; i <= s.size(); i++) {
      if (s[i] == '0' || s[i] == '1' || s[i] == '2' || s[i] == '3' ||
          s[i] == '4' || s[i] == '5' || s[i] == '6' || s[i] == '7' ||
          s[i] == '8' || s[i] == '9') {
        flag = 1;
      } else {
        flag = 0;
      }
    }
    if (flag == 1) {
      cout << "Yes" << endl;
    } else {
      cout << "No" << endl;
    }
  } else {
    cout << "No" << endl;
  }
  return 0;
}
