#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int a, b;
  string s;
  bool ans = false;
  cin >> a >> b;
  cin >> s;
  if (s.size() == a + b + 1 && s[a] == '-') {
    for (int i = 0; i < (int)a; i++) {
      if (1 <= s[i] - '0' && s[i] - '0' <= 9) {
        ans = true;
      } else {
        ans = false;
        break;
      }
    }
    for (int i = a + 1; i < (int)b; i++) {
      if (1 <= s[i] - '0' && s[i] - '0' <= 9) {
        ans = true;
      } else {
        ans = false;
        break;
      }
    }
  }
  if (ans)
    cout << "Yes" << endl;
  else
    cout << "No" << endl;
  return 0;
}
