#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  bool ok = false;
  for (int i = 0; i < s.size(); i++) {
    if (s[a] == '-') ok = true;
    if (!(s[i] >= '0' and s[i] <= '9')) ok = false;
  }
  cout << (ok ? "Yes" : "No");
  return 0;
}
