#include <bits/stdc++.h>
#define all(x) x.begin(),x.end()
using i64 = long long;
std::mt19937 rng(69);
int main()
{
int n;
std::cin>>n;
std::vector<int>extra(n);
int all_extra = 0;
for(int i=0;i<n;i++)
{
int a,b;
std::cin>>a>>b;
extra[i]=a-b;
all_extra+=extra[i];
}
std::vector<int>pq;
pq.push_back(0);
pq.push_back(0);
std::sort(all(pq));
for(int i=1;i<n;i++)
{
//
if(extra[i]<0)
{
//shitam la stanga totul
for(auto &c:pq)
{
c+=extra[i];
}
}
if(extra[i]>0)
{
for(int j=i;j<(int)pq.size();j++)
{
pq[j]+=extra[i];
}
}
//addaug pante
pq.push_back(0);
pq.push_back(0);
std::sort(all(pq));
}
int last=0,panta=-n;
i64 rez=0;
for(auto &c:pq)
{
c=std::min(c,all_extra);
if(c>last)
{
rez-=panta*(c-last);
last=c;
}
panta++;
}
rez-=panta*(all_extra-last);
//std::cout<<rez<<' ';
//calculez pl mea dp ul in all_extra
std::vector<int>need(n+1,0);
for(int i=0;i<n;i++)
{
if(extra[i]<0)
{
need[i]=-extra[i];
}
}
need[n]=all_extra+1;
for(int i=0,j=0;i<n;i++)
{
int xd=extra[i];
while(xd>0)
{
int mn=std::min(xd , need[j]);
need[j]-=mn;
xd-=mn;
rez+=abs(i-j)*mn;
///std::cout<<mn<<' '<<i<<' '<<j<<'\n';
while(need[j]==0)
{
j++;
}
}
}
std::cout<<rez;
}
/*
2
2 0
0 1
*/
