#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  const string num = "0123456789";
  string ret = "Yes";
  for (int i = 0; i < S.size(); i++) {
    if (i == A) {
      if (S[i] != '-') ret = "No";
    } else if (find(num.begin(), num.end(), S[i]) == num.end())
      ret = "No";
  }
  cout << ret << endl;
  return 0;
}
