#pragma GCC optimize("O3")
#include<bits/stdc++.h>
#define ll long long
#define endl "\n"
#define AI ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
using namespace std;
struct pr
{
ll a;
ll b;
};
int main()
{
AI
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
ll n,i,j,s,mx,mn;
cin>>n;
vector<pr>v(n);
for(i=0;i<n;i++)
cin>>v[i].a>>v[i].b;
ll ans=0;
for(i=1;i<(1<<n);i++)
{
s=0;
mx=0;
mn=1e9;
for(j=0;j<n;j++)
{
if(i&(1<<j))
{
s+=v[j].b;
mx=max(mx,v[j].a);
mn=min(mn,v[j].a);
}
}
ans=max(ans,s-mx+mn);
//cout<<ans<<' '<<s<<' '<<mx<<' '<<mn<<endl;
}
cout<<ans;
}
