#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  cin >> A >> B;
  char S[11];
  cin >> S;
  for (int i = 0; i < A; i++) {
    if (!('0' <= S[i] && S[i] <= '9')) {
      cout << "No" << endl;
    }
  }
  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;
    }
  }
  cout << "Yes" << endl;
}
