E_AC

#include <bits/stdc++.h>

#define ll long long

using namespace std;

int main(){
    ll v[1000010];
    ll n;

    cin >> n;

    for(int i=0; i<n; i++){
        cin >> v[i];
    }

    sort(v, v + n);

    ll mmax = v[0]+v[n-1];
    for(int i=1; i<n/2; i++){
        mmax=min(mmax, v[i]+v[n-i-1]);
    }

    cout << mmax << endl;

    return 0;
}