#include <bits/stdc++.h>
using namespace std;
int main() {
  int m, n;
  cin >> m >> n;
  string name;
  cin >> name;
  int k = 0, l = 0, i;
  if (name[m] == '-') k = 1;
  for (i = 0; i < name.size(); i++) {
    if (i == m) continue;
    if (name[i] == '0' || name[i] == '1' || name[i] == '2' || name[i] == '3' ||
        name[i] == '4' || name[i] == '5' || name[i] == '6' || name[i] == '7' ||
        name[i] == '8' || name[i] == '9') {
      l = 1;
    }
  }
  if (k == 1 && name.size() == m + n + 1 && l == 1)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
}
