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