#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  cin >> A >> B;
  char s[A + B + 2];
  int ans = 0;
  for (int i = 1; i <= A + B + 1; i++) {
    if (i == A + 1 && s[i] != '-') {
      ans = -1;
    } else if (i != A + 1 && s[i] == '-')
      ans = -1;
  }
  if (ans >= 0) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
  return 0;
}
