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