#pragma GCC optimize("Ofast") #include <bits/stdc++.h> using namespace std; #define endl "\n" #define creeper_bonc ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0); #define pb push_back #define fi first #define se second #define pii pair<int, int> #define all(v) (v).begin(), (v).end() #define ins insert #define nl endl //#define int long long const int imax = INT_MAX; const int imin = INT_MIN; void _() { int n; cin>>n; vector <pii> v; for(int i = 0;i < n;i++) cin>>v[i].fi>>v[i].se; sort(all(v)); int mx = imin, sum = 0, mx1 = imin; for(int i = 0;i < n;i++) { sum += v[i].se; mx1 = max(mx1, v[i].fi - (sum - v[i].se)); mx = max(mx, sum - v[i].fi + mx1); } cout<<mx; } signed main() { creeper_bonc int t=1; //cin>>t; while(t--) { _(); cout<<endl;} } /*Author: Davud*/