#include <bits/stdc++.h>
using namespace std;

void solve() {
  int a, b;
  cin >> a >> b;
  cout << ((a + 1 == b) ? "YES" : "NO") << endl;
  cout << a + 1 - b << endl;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  solve();
  getchar();
}