#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  char S[12];
  cin >> A >> B >> S;
  for (int i = 0; i < A; i++)
    if (!('0' <= S[i] && S[i] <= '9')) {
      cout << "No" << endl;
      return 0;
    }
  if (S[A] != '-') cout << "No" << endl;
  for (int i = A + 1; i < A + B; i++)
    if (!('0' <= S[i] && S[i] <= '9')) {
      cout << "No" << endl;
      return 0;
    }
  cout << "Yes" << endl;
}
