#include <bits/stdc++.h>
int main(int argc, char *argv[]) {
  int a, b;
  std::string s;
  std::cin >> a >> b >> s;
  int i = 1;
  std::string d = {"123456789"};
  for (auto &c : s) {
    if (i == (a + 1)) {
      if (c != '-') {
        std::cout << "No" << std::endl;
        return 0;
      }
    } else if (d.find(c) >= d.size()) {
      std::cout << "No" << std::endl;
      return 0;
    }
    ++i;
  }
  std::cout << "Yes" << std::endl;
}
