#include <bits/stdc++.h>
using namespace std;
int main() {
  int t, k, j, i, d, c = 0, a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  if (s[a] == '-') {
    for (j = a + 1; j < s.length(); j++) {
      if (s[j] >= '0' && s[j] <= '9') c++;
    }
    if (c == b)
      cout << "Yes\n";
    else
      cout << "No\n";
  } else
    cout << "No\n";
}
