#include <bits/stdc++.h>
int main() {
  int a, b;
  std::string s;
  std::cin >> a >> b >> s;
  std::string ans = "No";
  if (s[a] == '-') {
    s.erase(s.begin() + a);
    for (const auto x : s) {
      if ('0' <= x && x <= '9') {
        ans = "Yes";
      }
    }
  }
  std::cout << ans << std::endl;
  return 0;
}
