#pragma GCC optimize("O3")
#include <bits/stdc++.h>
#define ll long long
#define str string
#define pb push_back
#define pf push_front
#define in insert
#define all(v) v.begin(),v.end()
#define fastIO ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
const ll sz=1000000,INF=1000000000000000000;
using namespace std;
void solve()
{
ll n,num1,num2,minNum,maxNum,res,ans=-INF;
cin>>n;
vector<pair<ll,ll>>nums;
for(int i=0;i<n;i++)
{
cin>>num1>>num2;
nums.pb({num1,num2});
}
for(int i=1;i<pow(2,nums.size());i++)
{
minNum=INF,maxNum=-INF,res=0;
for(int j=0;j<nums.size();j++)
{
if(i&(ll)pow(2,j))
{
minNum=min(minNum,nums[j].first),maxNum=max(maxNum,nums[j].first),res+=nums[j].second;
}
}
ans=max(ans,res-(maxNum-minNum));
}
cout<<ans;
}
int main()
{
fastIO;
ll t=1;
//cin>>t;
while(t--)
{
solve();
}
}
