CodeForces 440A Forgotten Episode_forgotten episodec++-优快云博客

本文链接：https://blog.youkuaiyun.com/geekdoe/article/details/50556092

本文主要讲述了Polycarpus在观看一季包含n集的电视剧"Graph Theory"时，遗漏了最后一集。他已经观看了n-1集，通过已观看的集数列表，我们需要找出他忘记看的那集。

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Polycarpus adores TV series. Right now he is ready to finish watching a season of a popular sitcom "Graph Theory". In total, the season has n episodes, numbered with integers from 1 to n.

Polycarpus watches episodes not one by one but in a random order. He has already watched all the episodes except for one. Which episode has Polycaprus forgotten to watch?

Input

The first line of the input contains integer n (2 ≤ n ≤ 100000) — the number of episodes in a season. Assume that the episodes are numbered by integers from 1 to n.

The second line contains n - 1 integer a₁, a₂, ..., a_n (1 ≤ a_i ≤ n) — the numbers of episodes that Polycarpus has watched. All values of a_i are distinct.

Output

Print the number of the episode that Polycarpus hasn't watched.

Sample test(s)

Input

10
3 8 10 1 7 9 6 5 2

Output

4

#include<iostream>
using namespace std;
int num[100010];
int main(){
    int n,k,i;
    while(cin>>n){
        for(i=0;i<n;i++){
            cin>>k;
            num[k]=1;
        }
        for(i=1;i<=n;i++){
            if(!num[i]){
                cout<<i<<endl;
            }
        }
    }
    return 0;
}