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