#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string s;
  bool check = false;
  cin >> a >> b >> s;
  if (s[a] == '-') {
    for (int i = 0; i < a + b + 1; i++) {
      if (i != a + 1) {
        continue;
      }
      if ('0' <= s[i] && s[i] <= '9') {
        continue;
      } else {
        check = true;
      }
    }
  } else {
    check = true;
  }
  if (check) {
    cout << "No" << endl;
  } else {
    cout << "Yes" << endl;
  }
  return 0;
}
