#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const int MOD = 1000000007;
int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  int pos = 0;
  for (int i = 0; i < (int)S.size(); ++i)
    if (S[i] == '-') {
      pos = i;
      break;
    }
  if (pos == A)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
