#include<bits/stdc++.h>
#define REP(i,n) for(int i=0,i##_len=int(n);i<i##_len;++i)
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
#define All(x) (x).begin(),(x).end()
#define rAll(x) (x).rbegin(),(x).rend()
using namespace std;
using ll = long long;

int main(){
    int N;cin>>N;
    vector<ll> A(2*N);
    REP(i,2*N) cin>>A[i];
    int l=0,r=2*N-1;
    ll ans=0;
    while(l<r){
        ll L = A[l]-A[l+1],R = A[r]-A[r-1];
        if(L>R){
            ans+=L;
            l+=2;
        }
        else{
            ans+=R;
            r-=2;
        }
    }
    cout<<ans<<endl;
}