#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  int i, j, c = 0, l, m, n, f = 0;
  cin >> m >> n;
  cin >> a;
  if (a[m] == '-') f = 1;
  if (f == 1)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
