Problem:
Score : 300 points

Problem Statement

Takahashi made N problems for competitive programming.
The problems are numbered 1 to N, and the difficulty of Problem i is represented as an integer d_i (the higher, the harder).

He is dividing the problems into two categories by choosing an integer K, as follows:

A problem with difficulty K or higher will be for ARCs.

A problem with difficulty lower than K will be for ABCs.

How many choices of the integer K make the number of problems for ARCs and the number of problems for ABCs the same?

Problem Statement

2 \leq N \leq 10^5

N is an even number.

1 \leq d_i \leq 10^5

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
d_1 d_2 ... d_N

Output

Print the number of choices of the integer K that make the number of problems for ARCs and the number of problems for ABCs the same.

Sample Input 1

6
9 1 4 4 6 7

Sample Output 1

2

If we choose K=5 or 6, Problem 1, 5, and 6 will be for ARCs, Problem 2, 3, and 4 will be for ABCs, and the objective is achieved.
Thus, the answer is 2.

Sample Input 2

8
9 1 14 5 5 4 4 14

Sample Output 2

0

There may be no choice of the integer K that make the number of problems for ARCs and the number of problems for ABCs the same.

Sample Input 3

14
99592 10342 29105 78532 83018 11639 92015 77204 30914 21912 34519 80835 100000 1

Sample Output 3

42685

Solution in C++ (GCC 9.2.1) (judge verdict: Runtime Error)

//include
#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <cmath> 
#include <iomanip>
#include <math.h>
#include <utility>
#include <functional>
//using
using namespace std;
/*using vi = vector <int>;
using vs = vector <string>;
using vc = vector <char>;*/
using ll= long long;
using vvl = vector<vector<ll> >;
//define
#define int long long
#define rep(i,n) for(int i=0; i<n; i++)
#define print(n) cout<<n<<endl;
//グローバル変数宣言
int c=0,e=0,n=0,k=0;


signed main(){
   cin>>n;
   vector<int>a(n),b(n);
   rep(i,n)cin>>a[i];
   rep(i,n)b[a[i]-1]=i+1;
   rep(i,n)print(b[i]);
}