#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B, count = 0, flag = 0;
  char S[13];
  cin >> A;
  cin >> B;
  cin >> S;
  if (S[A] == '-' && (S[A + 1] != NULL && S[A + 1] != '-') &&
      (S[A + B] != NULL && S[A + B] != '-') && S[A + B + 1] == NULL) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
