#include <bits/stdc++.h>
using namespace std;
int main() {
  string s;
  int count = 0;
  int index;
  cin >> s;
  for (int i = 0; i < s.size(); i++) {
    if (s[i] == '-') {
      count++;
      index = i;
    }
  }
  if (count == 1 && index != 0 && index != s.size() - 1)
    cout << "Yes";
  else
    cout << "No";
  return 0;
}
