#include <bits/stdc++.h>
using namespace std;
string str1;
int main(int argc, char const *argv[]) {
  int a, b;
  cin >> a >> b;
  cin >> str1;
  int len = str1.length();
  for (int i = 0; i < len; i++) {
    if (str1[a] == '-')
      cout << "Yes" << endl;
    else
      cout << "No" << endl;
    break;
  }
  return 0;
}
