#include <bits/stdc++.h> using namespace std; #define int long long typedef long long ll; typedef pair <ll, ll> pii; #define fi first #define se second #define pb push_back signed main(){ ios_base::sync_with_stdio(0); cin.tie(0); int n; cin >>n; vector <pii> v; v.pb({0, 0}); for(int i = 1 ; i <= n ; i++){ int a, b; cin >> a >> b; v.pb({a, b}); } sort(v.begin(), v.end()); ll pref[5005]; pref[0] = 0; for(int i = 1 ; i <= n ; i++)pref[i] = pref[i - 1] + v[i].se; ll ans = 0; for(int i = 1 ; i <= n; i++){ for(int j = i ; j <= n ; j++){ ans = max(ans, pref[j] - pref[i - 1] - v[j].fi + v[i].fi); } } cout << ans << endl; return 0; }