#include <bits/stdc++.h> // solved by bekagg #define int long long #define ent '\n' #define pb push_back #define all(x) x.begin(),x.end() #define PRaim_bek_abi ios_base::sync_with_stdio(0);cin.tie(0); using namespace std; const int N = 5e5+5; const int MOD = 1e9+7; int n , pref[N]; vector<pair<int , int> > v; void arkanefury228(){ cin >> n; int ans = 0; for (int i = 1; i <= n; i++){ int a , b; cin >> a >> b; ans = max(ans , b); v.pb({a , b}); } sort(all(v)); multiset<int>s; for (int i = 1; i <= n; i++){ pref[i] = pref[i - 1] + v[i - 1].second; s.insert(pref[i] - (v[i - 1].first - v[0].first)); } int sum = 0; ans = max(ans , *s.rbegin()); for (int i = 1; i < n; i++){ s.erase(s.find(pref[i] - (v[i - 1].first - v[0].first))); sum += (v[i].first - v[i - 1].first); sum -= v[i - 1].second; ans = max(ans , *s.rbegin() + sum); } cout << ans; } signed main(){ PRaim_bek_abi int t=1; //cin>>t; for (int respagold = 1; respagold <= t; respagold++) arkanefury228(); }