#include <bits/stdc++.h>
using namespace std;
int main() {
ifstream cin("restack.in");
ofstream cout("restack.out");
int n, c = 0, ans = 0; cin >> n;
vector<int> v;
for (int i = 0; i < n; i++) {
int a, b; cin >> a >> b;
v.push_back(c += a - b);
}
sort(v.begin(), v.end());
for (int i = 0; i < n; i++) ans += abs(v[i] - v[n / 2]);
cout << ans << '\n';
}