#include <bits/stdc++.h> using namespace std; typedef long long ll; const ll N = 5e5+5, MAX = 3e4+5, ZERO = 3e4, INF = 1e18; ll n, delta; ll val[N], pref[N]; void read() { cin >> n; for(int i = 1; i <= n; i++) { ll a, b; cin >> a >> b; val[i] = a - b; } } void solve() { pref[0] = 0; for(int i = 1; i <= n; i++) { pref[i] = pref[i-1] + val[i]; } delta = pref[n]; ll ans = 0, x; priority_queue<ll> pq; pq.push(0); for(int i = 1; i <= n; i++) { x = pref[i]; if(x < 0) { ans += -x; x = 0; } else if(x > delta) { ans += x - delta; x = delta; } pq.push(x); pq.push(x); ans += pq.top() - x; pq.pop(); } cout << ans << '\n'; } int main() { ios::sync_with_stdio(0); cin.tie(0); read(); solve(); return 0; }