#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define ll long long
//#define int long long
const ll mod=998244353;
const int mxsz=2e5+4;
const ll inf =1e9+4;
signed main(){
ios::sync_with_stdio(0);
cin.tie(0);
cout.tie(0);
int n;
cin>>n;
pair<int,int>a[n];
for (int i=0;i<n;i++){
cin>>a[i].first>>a[i].second;
}
vector<int>ans;int c=0;
for (int i=1;i<(1<<n);i++){
vector<int>cur;
int sum=0;
for (int j=0;j<n;j++){
if ((1<<j)&i){
cur.pb(a[j].first);
sum+=a[j].second;
}
}
int mn=inf,mx=0;
for (auto x:cur){
//cout<<x<<" ";
mn=min(mn,x);
mx=max(mx,x);
}//cout<<endl;
//cout<<mx<<" "<<mn<<endl;
if (sum-(mx-mn)>c){
c=sum-(mx-mn);
ans=cur;
}
}
cout<<c<<endl;
return 0;
}
