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