#include <bits/stdc++.h>
using namespace std;
int main() {
  int A, B;
  cin >> A >> B;
  string S;
  cin >> S;
  for (int i = 0; i < A; i++) {
    if (S[i] == '0' || S[i] == '1' || S[i] == '2' || S[i] == '3' ||
        S[i] == '4' || S[i] == '5' || S[i] == '6' || S[i] == '7' ||
        S[i] == '8' || S[i] == '9') {
    } else {
      cout << "No" << endl;
      goto end;
    }
  }
  goto next_1;
next_1:
  if (S[A] == '-') {
    goto next_2;
  } else {
    cout << "No" << endl;
    goto end;
  }
next_2:
  for (int i = A + 1; i < B; i++) {
    if (S[i] == '0' || S[i] == '1' || S[i] == '2' || S[i] == '3' ||
        S[i] == '4' || S[i] == '5' || S[i] == '6' || S[i] == '7' ||
        S[i] == '8' || S[i] == '9') {
    } else {
      cout << "No" << endl;
      goto end;
    }
  }
  goto next_3;
next_3:
  cout << "Yes" << endl;
end:
  return 0;
}
