#include <bits/stdc++.h> #define ll long long using namespace std; const ll N = 1e6, mod = 1e9 + 7, inf = 1e18; int main() { ios_base::sync_with_stdio(false); cin.tie(nullptr); int n; cin >> n; vector<ll> a(n); vector<ll> b(n); vector<pair<ll, ll>> p(n); for (int i = 0; i < n; i++) { cin >> a[i] >> b[i]; p[i] = {a[i], b[i]}; } vector<ll> prefsum(n + 1, 0); sort(p.begin(), p.end()); for (int i = 0; i < n; i++) { prefsum[i + 1] = prefsum[i] + p[i].second; } vector<ll> v; vector<ll> prefm(n, 0); ll mxd = -1; ll e = prefsum[n] - (p[n - 1].first - p[0].first); for (int i = 0; i < n; i++) { v.push_back(p[i].first - p[0].first - prefsum[i]); mxd = max(mxd, v.back()); prefm[i] = mxd; } ll ans = e; for (int i = n - 1; i >= 1; i--) { ll d = p[n - 1].first - p[i].first - (prefsum[n] - prefsum[i + 1]); ans = max(ans, p[i].second); ans = max(ans, e + prefm[i - 1] + d); } cout << ans << '\n'; }