#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  string S;
  cin >> A >> B >> S;
  bool b = 1;
  if (S.at(A) == '-') {
    for (int i = 0; i < A + B; i++) {
      if (i != A) {
        if (S.at(i) == 0 || S.at(i) == 1 || S.at(i) == 2 || S.at(i) == 3 ||
            S.at(i) == 4 || S.at(i) == 5 || S.at(i) == 6 || S.at(i) == 7 ||
            S.at(i) == 8 || S.at(i) == 9) {
        } else {
          b = 0;
        }
      }
    }
    if (b) cout << "Yes" << endl;
  } else
    cout << "No" << endl;
}
