#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define pll pair<ll,ll>
#define fs first
#define sc second
/*
void solve(){
ll n;
cin>>n;
pll arr[n];
for(auto &i:arr){
cin>>i.fs>>i.sc;
}
sort(arr,arr+n);
ll pref[n];
pref[0] = arr[0].sc;
for(int i = 1;i<n;i++)pref[i] = pref[i-1]+arr[i].sc;
ll ans = pref[0];
ll big = arr[0].fs;
for(int i = 1;i<n;i++){
ans = max(ans,big+pref[i]-arr[i].fs);
big = max(big,-pref[i-1]+arr[i].fs);
}
cout<<ans<<endl;
}
*/
void solve(){
ll n;
cin>>n;
pll arr[n];
for(auto &i:arr)cin>>i.fs>>i.sc;
ll ans = LLONG_MIN;
for(ll i = 1;i<(1LL<<n);i++){
ll amax = 0,amin = 1e18;
ll sum = 0;
for(int j = 0;j<n;j++){
if(i&(1LL<<j))sum += arr[j].sc,amin = min(amin,arr[j].fs),amax = max(amax,arr[j].fs);
}
ans = max(ans,sum-amax+amin);
}
cout<<ans;
}
int main(){
ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
int t = 1;
while(t--)solve();
}
