#include <bits/stdc++.h>   using namespace std;   map<int, int> mp;   int main() {     ios::sync_with_stdio(false);     cin.tie(0);     int n;     cin >> n;     for (int i = 1; i <= n; i++) {       int num;       cin >> num;       mp[num]++;     }     if (mp.size() != 2) {       cout <<  NO ;       exit(0);     }     if (mp.begin()->second != mp.rbegin()->second) {       cout <<  NO ;       exit(0);     }     cout <<  YES n ;     cout << mp.begin()->first <<     << mp.rbegin()->first;     return 0;   }   