#include<bits/stdc++.h>
using namespace std;
using i64 = int_fast64_t;
#define rep(i, N) for(int (i) = 0; (i) < (N); (i)++)
#define all(v) (v).begin(), (v).end()
#define eb emplace_back

i64 f(int& N, deque<i64> dq){
    i64 tem = 0, hom = 0;
    rep(i, N){
        size_t sz = dq.size(); 
        if(dq[0] - dq[1] >= dq[sz - 1] - dq[sz - 2]){
            hom += dq[0];
            tem += dq[1];
            rep(i, 2) dq.pop_front();
        } else {
            hom += dq[sz - 1];
            tem += dq[sz - 2];
            rep(i, 2) dq.pop_back();
        }
    }
    return hom - tem;
}

i64 g(int& N, deque<i64> dq){
    i64 tem = 0, hom = 0;
    rep(i, N){
        size_t sz = dq.size(); 
        if(dq[1] <= dq[sz - 2]){
            hom += dq[0];
            tem += dq[1];
            rep(i, 2) dq.pop_front();
        } else {
            hom += dq[sz - 1];
            tem += dq[sz - 2];
            rep(i, 2) dq.pop_back();
        }
    }
    return hom - tem;
}

int main(){
    int N;
    cin >> N;
    deque<i64> dq(2*N);
    rep(i, 2*N) cin >> dq[i];

    cout << max(f(N, dq), g(N, dq)) << endl;
}