#include <bits/stdc++.h>
using namespace std;
int A, B;
char s[12];
int main() {
  cin >> A >> B;
  cin >> s;
  for (int i = 0; i < A; i++) {
    if (!(0 <= s[i] && s[i] <= 9)) {
      cout << "No" << endl;
      return 0;
    }
  }
  if (s[A] != '-') {
    cout << "No" << endl;
    return 0;
  }
  for (int i = A + 1; i <= A + B; i++) {
    if (!(0 <= s[i] && s[i] <= 9)) {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
}
