#include <bits/stdc++.h>   using namespace std;   template <class L, class R>   ostream &operator<<(ostream &os, pair<L, R> P) {     return os <<  (  << P.first <<  ,  << P.second <<  ) ;   }   template <class T>   ostream &operator<<(ostream &os, vector<T> V) {     os <<  [ ;     for (auto vv : V) os << vv <<  , ;     return os <<  ] ;   }   template <class TH>   void _dbg(const char *sdbg, TH h) {     cerr << sdbg <<  =  << h <<   n ;   }   template <class TH, class... TA>   void _dbg(const char *sdbg, TH h, TA... a) {     while (*sdbg !=  , ) cerr << *sdbg++;     cerr <<  =  << h <<  , ;     _dbg(sdbg + 1, a...);   }   const long long N = 4e5 + 7;   long long n, a[N], pre[N], ansLen, ansIdx;   double ans = -1.0;   double sum(long long l, long long r) {     return pre[r] - (l > 0 ? pre[l - 1] : 0);   }   double f(long long len, long long idx) {     double ret = pre[idx] - pre[idx - len - 1];     ret += pre[n] - pre[n - len];     ret /= len + len + 1;     ret -= a[idx];     if (ret > ans) {       ans = ret;       ansIdx = idx;       ansLen = len;     }     return ret;   }   signed main() {     ios_base::sync_with_stdio(false);     cin.tie(NULL);     cout.tie(NULL);     ;     cin >> n;     for (long long i = 1; i <= n; i++) cin >> a[i];     sort(a + 1, a + n + 1);     for (long long i = 1; i <= n; i++) pre[i] = a[i] + pre[i - 1];     for (long long i = 1; i <= n; i++) {       long long cnt = min(i - 1, n - i);       long long lo = 0, hi = cnt;       while (hi - lo > 3) {         long long m1 = lo + (hi - lo) / 3, m2 = hi - (hi - lo) / 3;         if (f(m1, i) < f(m2, i))           lo = m1;         else           hi = m2;       }       for (long long k = lo; k <= hi; k++) f(k, i);     }     cout << 2 * ansLen + 1 <<   n ;     for (long long i = ansIdx; i >= ansIdx - ansLen; i--) cout << a[i] <<    ;     for (long long i = n - ansLen + 1; i <= n; i++) cout << a[i] <<    ;     return 0;   }   