#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  cin >> a >> b;
  string s;
  bool ans = true;
  if (s.at(a) != '-') {
    ans = false;
  }
  for (int i = 0; i < a; i++) {
    if (s.at(i) == '-') {
      ans = false;
    }
  }
  for (int i = a + 1; i < a + b + 1; i++) {
    if (s.at(i) == '-') {
      ans = false;
    }
  }
  cout << (ans ? "Yes" : "No") << endl;
}
