#include <bits/stdc++.h>
using namespace std;
int main() {
  int a, b;
  cin >> a >> b;
  string s;
  cin >> s;
  bool acceptable = 1;
  set<char> numbers;
  numbers.insert('1');
  numbers.insert('2');
  numbers.insert('3');
  numbers.insert('4');
  numbers.insert('5');
  numbers.insert('6');
  numbers.insert('7');
  numbers.insert('8');
  numbers.insert('9');
  for (int i = 0; i < a + b + 1; i++) {
    if (i == a) {
      if (s.at(i) != '-') {
        acceptable = 0;
      }
    } else {
      if (!(numbers.count(s.at(i)))) {
        acceptable = 0;
      }
    }
  }
  if (acceptable) {
    cout << "Yes" << endl;
  } else {
    cout << "No" << endl;
  }
}
