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