#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  for (int i = 0; i < A + B + 1; i++) {
    char a;
    cin >> a;
    if ((i == A && a != '-') || (i != A && a == '-')) {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
}
