# Odd one Out

__ Problem:-__

Alice and Bob are getting bored so they decided to play a game.

Alice has n cards having the first n odd numbers written on them. He removes one of the cards at random and hands the remaining n-1 cards to Bob. Help Bob to find the value of the card Alice has removed.

Input

The first line contains n the numbers of cards Alice has.

The second line contains n-1 space-separated integers representing the values of cards that Bob got.

Output

Print the value of card Alice removed.

Constraints

$1\le n\le 4000000$

Time Limit: 1

Memory Limit: 512

Source Limit:

Explanation

The first 5 odd numbers are 1, 3, 5, 7 and 9 out of which 7 is missing.

__Code (c++):-__

#include<iostream>

using namespace std;

int main()

{

// these three lines only for decrease the time

ios_base::sync_with_stdio(false);

cin.tie(0);

cout.tie(0);

long long n,sum=0,a;

cin>>n;

for(long long i=0;i<n–1;i++)

{

cin>>a;

sum=sum+a;

}

cout<<n*n–sum;

return 0;

}

__Code (c):-__

#include <stdio.h>

int main(){

long n,d;

scanf(“%ld”, &n);

long tot=n*n,sum=0;

for (int i=0;i<n–1;i++)

{

scanf(“%ld”,&d);

sum+=d;

}

printf(“%ldn”,tot – sum);

}