#include <iostream>

using namespace std;

void processVec(int, int*);

int main()
{
    int n;

    cin >> n;

    int v[n + 1];

    for (int i =0; i< n * 2; i++) {
        cin>> v[i];
    }

    processVec(n * 2, v);

    return 0;
}

void processVec(int n, int *v) {

    int middleR = n / 2;

    int middleL = middleR - 1;

    int count = 0;

    while (middleL >= 0 && middleR < n) {
        if(v[middleL] > v[middleR]) {
            count += v[middleL] - v[middleR];
        }
        middleL--;
        middleR++;

    }

    cout<<count;

}