#include <bits/stdc++.h> #define endl '\n' #define all(v) v.begin(),v.end() #define rall(v) v.rbegin(),v.rend() #define F first #define S second #define pf push_front #define pb push_back #define ll long long #define ull unsigned long long #define ld long double #define int long long #define vi vector <int> #define pii pair <int,int> #define tiii tuple<int,int,int> #define yes cout << "Yes" << endl #define no cout << "No" << endl #define YES cout << "YES" << endl #define NO cout << "NO" << endl #define out(v) for (auto x:v) cout << x << ' ' #define out1(v) for (auto x:v) cout << x << endl #define inp(arr) for (int i=0;i<arr.size();i++) cin>>arr[i] const int MAX=1e7+7; const int MOD=1e9+7; using namespace std; const int inf=1e18; int lejandr(int a,int b){ int sum=0; while(a>0){ a/=b; sum+=a; } return sum; } void solve(){ int n; cin>>n; vector<pii> vt(n); for(int i=0;i<n;i++){ cin>>vt[i].F>>vt[i].S; } int ans=-1; for(int i=0;i<n;i++){ for(int j=0;j<n;j++){ if(i!=j){ ans=max(ans,vt[i].S+vt[j].S-max(vt[i].F,vt[j].F)+min(vt[i].F,vt[j].F)); } } } cout<<ans<<endl; } signed main(){ ios_base::sync_with_stdio(0); cin.tie(nullptr); int t=1; //cin>>t; while(t--) { solve(); } }