#include <bits/stdc++.h> using namespace std; // #pragma GCC optimize("Ofast") // #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma") // #pragma GCC optimize("unroll-loops") #define ll long long #define int128 __int128_t #define pii pair<int, int> #define int long long #define pb push_back #define F first #define S second #define all(v) (v).begin(), (v).end() #define rall(v) (v).begin(), (v).end() #define MOD 1000000007 #define INF (ll)1e18 #define RINF (ll) - 1e18 void cinv(vector<int> &a, int n){for (int i = 0; i < n; i++){cin >> a[i];}} void coutv(vector<int> &a, int n){for (int i = 0; i < n; i++){cout << a[i] << " ";}} void solve() { int n; cin>>n; vector<pair<int,int>>a; vector<int>d; a.push_back({0,0}); for(int i = 1;i<=n;i++){ int x,y; cin>>x>>y; a.push_back({x,y}); } sort(a.begin(),a.end()); for(int i = 1;i<=n;i++){ a[i].S = a[i-1].S+a[i].S; d.push_back(a[i-1].S-a[i].F); } int d1 = 0; int h = 1e18; for(int i = 1;i<=n;i++){ int g = a[i].S-a[i].F; h = min(h,d[i-1]); d1 = max(d1,g-h); // cout<<d[i-1]<<" "<<g<<" "<<i<<" "<<a[i].F<<" "<<a[i].S<<endl; } cout<<d1<<endl; } signed main() { ios_base::sync_with_stdio(false); cin.tie(NULL); int t = 1; // cin >> t; while (t--) { solve(); } }