//#include<bits/stdc++.h>

 #include<set>

 #include<iostream>

 #include<stdio.h>

 #include<stdlib.h>

 #include<cstring>

 #include<stack>

 #include<algorithm>

 using namespace std;

 int n;

 int val[];

 set<int>sss;

 set<int>::iterator iter;

 int main()

 {

     scanf("%d", &n);

     for(int i = ; i < n; i++){

         scanf("%d", &val[i]);

         sss.insert(val[i]);

     }

     printf("%d\n", sss.size());

     for(iter = sss.begin(); iter != sss.end(); iter++){

         printf("%d ", *iter);

     }

     cout<<endl;

     return ;

 }

 //#include<bits/stdc++.h>

 #include<set>

 #include<iostream>

 #include<stdio.h>

 #include<stdlib.h>

 #include<cstring>

 #include<stack>

 #include<algorithm>

 using namespace std;

 int n, m;

 struct p{

     int id;

     int s;

 }peo[];

 bool cmp(p a, p b)

 {

     if(a.s == b.s)return a.id < b.id;

     else return a.s > b.s;

 }

 int main()

 {

     scanf("%d%d", &n, &m);

     for(int i = ; i < n; i++){

         scanf("%d%d", &peo[i].id, &peo[i].s);

     }

     sort(peo, peo + n, cmp);

     int in = m * 1.5;

     int ins = peo[in - ].s, i = in;

     while(i < n && peo[i].s == ins){

         i++;

         in++;

     }

     printf("%d %d\n", ins, in);

     for(int j = ; j < in; j++){

         printf("%d %d\n", peo[j].id, peo[j].s);

     }

     return ;

 }

 import java.io.EOFException;

 import java.math.BigDecimal;

 import java.math.BigInteger;

 import java.util.Scanner;

 public class Main {

     static int n;

     static public void main(String[] args){

         Scanner scan = new Scanner(System.in);

         n = scan.nextInt();

         int id = 0;

         BigInteger mmm = BigInteger.ZERO;

         for(int i = 0; i < n; i++){

             BigInteger tmp = scan.nextBigInteger();

             if(tmp.compareTo(mmm) > 0){

                 mmm = tmp;

                 id = i + 1;

             }

         }

         System.out.println(id);

         System.out.println(mmm);

         scan.close();

     }

 }