#include <bits/stdc++.h>
using namespace std;

int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  for (int i = 0; i < A + B + 1; i++) {
    if (i == A && S[i] != '-' || i != A && !isdigit(S[i])) {
      cout << "No" << endl;
      return 0;
    }
  }
  cout << "Yes" << endl;
}