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