Codeforces Round #481 (Div. 3) A. Remove Duplicates vis[a[i]]

Petya has an array $a$ consisting of $n$ integers. He wants to remove duplicate (equal) elements.

Petya wants to leave only the rightmost entry (occurrence) for each element of the array. The relative order of the remaining unique elements should not be changed.

Input

The first line contains a single integer $n$ ($1\le n\le 50$) — the number of elements in Petya's array.

The following line contains a sequence $a_1,a_2,\dots ,a_n$ ($1\le a_i\le 1000$) — the Petya's array.

Output

In the first line print integer $x$ — the number of elements which will be left in Petya's array after he removed the duplicates.

In the second line print $x$ integers separated with a space — Petya's array after he removed the duplicates. For each unique element only the rightmost entry should be left.

Examples

input

Copy

6
1 5 5 1 6 1

output

Copy

3
5 6 1 

input

Copy

5
2 4 2 4 4

output

Copy

2
2 4 

input

Copy

5
6 6 6 6 6

output

Copy

1
6 

Note

In the first example you should remove two integers $1$, which are in the positions $1$ and $4$. Also you should remove the integer $5$, which is in the position $2$.

In the second example you should remove integer $2$, which is in the position $1$, and two integers $4$, which are in the positions $2$ and $4$.

In the third example you should remove four integers $6$, which are in the positions $1$, $2$, $3$ and $4$.

题意：给出一个序列，写出该序列中的数字最后出现的顺序。

思路:刚开始的时候很无奈，后面想到了vis[a[i]]来判断是否出现，！！！好长时间不写退化了

#include<bits/stdc++.h>
using namespace std;
int flag[1005];
int a[55];
int b[55];
int cnt=0;
set<int> s;
int main(){
    int n;
    scanf("%d",&n);
    for(int i=0;i<n;i++){
        scanf("%d",&a[i]);
        s.insert(a[i]);
    }
    printf("%d\n",s.size());
    for(int i=n-1;i>=0;i--){
        if(flag[a[i]]==0){
            flag[a[i]]=1;
            b[cnt++]=a[i];
        }
    }
    for(int i=cnt-1;i>=0;i--){
        if(i==cnt-1)
            printf("%d",b[i]);
        else
            printf(" %d",b[i]);
    }
    printf("\n");
}