#include <bits/stdc++.h>
using namespace std;
using ll=long long;
#define in insert
#define pb push_back
void solve(){
ll n;
cin>>n;
vector<pair<ll,ll>>v(n);
for(int i=0;i<n;i++){
cin>>v[i].first>>v[i].second;
}
ll ans=0;
for(int i=1;i<(1<<n);i++){
ll maks=LLONG_MIN;
ll mini=LLONG_MAX;
ll sum=0;
for(int j=0;j<n;j++){
if((i&(1<<j))!=0){
maks=max(maks,v[j].first);
mini=min(mini,v[j].first);
sum+=v[j].second;
}
}
ans=max(ans,sum-maks+mini);
}
cout<<ans;
}
int main(){
ll t=1;
while(t--){
solve();
cout<<'\n';
}
}
