#include <bits/stdc++.h>
using namespace std;
int main() {
  string a;
  int i, j, l, m, n, f = 0;
  cin >> m >> n;
  cin >> a;
  for (i = 0; i < a.size(); i++) {
    if (a[i] == '-')
      f = 1;
    else if (f == 1 && a[i] >= '0' && a[i] <= '9')
      f = 2;
  }
  if (f == 2)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
