#include <bits/stdc++.h> using namespace std; typedef long long ll; int main(){ ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0); int nums; cin >> nums; vector<pair<ll, ll>> vec(nums + 1); for (int i = 1; i <= nums; i++){ ll s, v; cin >> s >> v; vec[i] = {s, v}; } sort(vec.begin() + 1, vec.end()); vector<ll> pref(nums + 1); multiset<ll> s; pref[0] = 0; for (int i = 1; i <= nums; i++){ pref[i] = pref[i - 1] + vec[i].second; s.insert(pref[i] - vec[i].first); } ll ans = 0; for (int i = 1; i <= nums; i++){ ans = max(ans, *s.rbegin() - pref[i - 1] + vec[i].first); s.erase(s.find(pref[i] - vec[i].first)); } cout << ans; }