#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <functional>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <deque>

#include <map>

#include <cctype>

#include <stack>

#include <sstream>

using namespace std ;

typedef long long LL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 0x3f3f3f3f3f3f;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 1e5 + 5;

const int mod = 1e9 + 7;

const char *mark = "+-*";

const int dr[] = {-1, 0, 1, 0};

const int dc[] = {0, 1, 0, -1};

int n, m;

inline bool is_in(int r, int c){

    return r >= 0 && r < n && c >= 0 && c < m;

}

inline int Min(int a, int b){ return a < b ? a : b; }

inline int Max(int a, int b){ return a > b ? a : b; }

int a[maxn];

int main(){

    while(scanf("%d", &n) == 1){

        for(int i = 0; i < n; ++i)  scanf("%d", &a[i]);

        sort(a, a+n);

        int ans = INF;

        for(int i = 0; i < n/2; ++i){

            ans = Min(ans, a[i]+a[n-i-1]);

        }

        printf("%d\n", ans);

    }

    return 0;

}