#include <bits/stdc++.h> #define ll long long using namespace std; int main() { ios_base::sync_with_stdio(0); cin.tie(nullptr); ll n; cin >> n; vector<ll> a(n), b(n); vector<pair<ll, ll>> v; for (ll i = 0; i < n; i++) { cin >> a[i] >> b[i]; v.push_back({a[i], -b[i]}); } sort(v.begin(), v.end()); ll ans = 0, sum = 0, mx = -1e18, mn = 1e18; for (ll i = 0; i < n; i++) { sum += -v[i].second; mx = max(mx, v[i].first); mn = min(mn, v[i].first); ans = max(ans, sum - (mx - mn)); } cout << ans; }