#include<bits/stdc++.h>
using namespace std;
#define int long long
int n, a[100010], b[100010], c[100010];
signed main() {
	freopen("snack.in", "r", stdin);
	freopen("snack.out", "w", stdout);
    cin >> n;
    for(int i = 1; i <= n; i ++) {
        cin >> a[i] >> b[i];   //c为前缀和数组 
        c[i] = c[i - 1] + b[i - 1] - a[i - 1];   //求出前i堆剩余多少 
	}
    sort(c + 1, c + n + 1);
    int mid = c[(n + 1) / 2], m, ans = 0;  //找中位数 
    m = -mid;
    for(int i = 1; i <= n; i ++) {
        ans += abs(c[i] + m);
	}
    cout << ans << endl;
    return 0;
}