#include <bits/stdc++.h> #define ll long long using namespace std; int main() { int n; cin >> n; pair<ll, ll> a[n + 1]; for(int i = 1; i <= n; ++i) cin >> a[i].first >> a[i].second; // cost -> -a[i].fi + prefval[i] - mn // mn -> preval[j] - a[j].fi sort(a + 1, a + n + 1); ll mn = 0, val = 0, res = 0; for(int i = 1; i <= n; ++i) { mn = min(mn, val - a[i].first); val += a[i].second; res = max(res, -a[i].first + val - mn); } cout << res << endl; }