mission

#include<stdio.h>
#include<algorithm>
using namespace std;
typedef long long int ll;

struct elem{
    ll eng,exp;
};

bool mycmp(elem a,elem b){
    ll ca = a.exp - 2*a.eng;
    ll cb = b.exp - 2*b.eng;
    return ca > cb;
}

int main()
{
    int n;
    scanf("%d",&n);
    ll penalty[n+1];
    penalty[0] = 0;
    elem arr[n+1];
    for(ll i = 1 ; i <= n ; i ++){
        penalty[i] = i*i;
        scanf("%lld %lld",&arr[i].eng,&arr[i].exp);
    }
    sort(arr+1,arr+1+n,mycmp);

    ll sum = 0;
    ll cnt = 0;
    for(int i = 1 ; i <= n ; i ++){
        ll now = arr[i].exp - 2*arr[i].eng;
        if(sum + now - penalty[n - cnt - 1] >= sum - penalty[n - cnt]){
            sum += now;
            cnt++;
        }else{
            break;
        }

    }
    printf("%lld",sum - penalty[n-cnt]);
    return 0;
}