#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  string s;
  cin >> a >> b >> s;
  string ans = "No";
  if (s[a] == '-') {
    for (int i = (int)0; i < (int)a; ++i) {
      if (s[i] >= '0' && s[i] <= '9') {
        ans = "Yes";
      } else {
        ans = "No";
      }
    }
    for (int i = (int)a + 1; i < (int)a + b; ++i) {
      if (s[i] >= '0' && s[i] <= '9') {
        ans = "Yes";
      } else {
        ans = "No";
      }
    }
  }
  cout << ans << endl;
}
