/* Zadanie: Art Exhibition Autor: Tomasz Kwiatkowski */ #include <bits/stdc++.h> #define fi first #define se second #define pb push_back using namespace std; typedef long long ll; const int MAXN = 1e6 + 7; const int INF = 1e9 + 7; int main() { ios_base::sync_with_stdio(0), cin.tie(0); int n; cin >> n; vector<pair<ll, ll>> artworks(n); for (auto& [a, b] : artworks) cin >> a >> b; sort(artworks.begin(), artworks.end()); ll maxx = -1e18; ll ans = 0; ll pref = 0; for (auto [a, b] : artworks) { maxx = max(a - pref, maxx); pref += b; ans = max(maxx + pref - a, ans); } cout << ans << '\n'; return 0; }