//AzaLE (Azamat Alisherov)
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <bits/stdc++.h>
using namespace std;
using namespace __gnu_pbds;
#pragma GCC optimize("Ofast,unroll-loops")
#define size(x) (int)x.size()
#define int long long
//#define endl '\n'
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define F first
#define S second
template<class T> using oset = tree<T, null_type, less_equal<T>,
rb_tree_tag, tree_order_statistics_node_update>;
const int MOD = 1e9 + 7;// 119 * (1 << 23) + 1;
int binpow (int a, int n){
int res = 1;
while (n){
if (n & 1){
res = (res * a) % MOD;
}
a = (a * a) % MOD;
n >>= 1;
}
return res % MOD;
}
void chomp(){
int n;
cin >> n;
vector <pair<int, int>> p(n);
for(int i = 0; i < n; i++){
cin >> p[i].F >> p[i].S;
}
sort(rall(p));
int ans = 0;
for(int i = 0; i < n; i++){
int sm = 0;
int mn = 1e18;
int mx = 0;
//cout << i << endl;
for(int j = i; j < n; j++){
mn = min(mn, p[j].F);
mx = max(mx, p[j].F);
sm += p[j].S;
//cout << sm << " " << mn << " " << mx << " " << sm - abs(mx - mn) << endl;
ans = max(ans, sm - abs(mx - mn));
}
}
cout << ans;
}
signed main(){
//ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
int tasks = 1;
//cin >> tasks;
while(tasks--){
chomp();
}
}
/*
*/
