#pragma GCC optimize("O3") #pragma GCC optimize("unroll-loops") #include <bits/stdc++.h> using namespace std; #define pb push_back #define all(a) a.begin(),a.end() typedef long long ll; typedef pair<int,int> pii; typedef pair<ll,ll> pll; typedef unsigned long long ull; typedef vector<int> vi; void solve(){ int n; cin >> n; vector<ll> pref(n+1,0); priority_queue<ll> pq; ll ans = 0; for(int i = 1; i <= n; i++){ int a,b; cin >> a >> b; pref[i] = a-b + pref[i-1]; } for(int i = 1; i <= n; i++){ if(pref[i] < 0){ ans += -pref[i]; pref[i] = 0; }else if(pref[i] > pref[n]){ ans += pref[i]-pref[n]; pref[i] = pref[n]; } pq.push(pref[i]); if(pq.top() > pref[i]){ ans += pq.top() - pref[i]; pq.pop(); pq.push(pref[i]); } } cout << ans; } signed main(){ cin.tie(0)->sync_with_stdio(0); int t = 1; // cin >> t; while(t--){solve();} }