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