#include <bits/stdc++.h>
using namespace std;
int main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  ;
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool is_format = false;
  if (s[a] == '-') {
    for (int i = a + 1; i < s.size(); ++i) {
      if (s[i] >= '0' && s[i] <= '9') is_format = true;
    }
    is_format ? cout << "Yes"
                     << "\n"
              : cout << "No"
                     << "\n";
  } else
    cout << "No"
         << "\n";
  return 0;
}
