#include <bits/stdc++.h>
using namespace std;
bool myStrcmp(string str, int range) {
  bool bRtn = true;
  for (int i = 0; i < str.size(); i++) {
    if (!isdigit(str[i])) {
      bRtn = false;
    }
  }
  return bRtn;
}
int main() {
  unsigned int A = 0, B = 0;
  cin >> A >> B;
  string str = {};
  cin >> str;
  if (strcmp(&str[A], "-") && str.size() == A + B + 1) {
    if (myStrcmp(str.substr(0, A), A) &&
        myStrcmp(str.substr(A + 1, A + B + 1), A + B + 1)) {
      cout << "Yes" << endl;
      return 0;
    }
  }
  cout << "No" << endl;
  return 0;
}
