#include<iostream>
#include<cmath>
using namespace std;
int pool[20001];
int main()
{
	int n,p,ans=0;
	cin>>n;
	int x,y;
	for(int i=1;i<=n;i++)
	{
		cin>>x>>y;
		pool[y+10001]++;
	}
	int s=0;
	for(int i=1;i<=20001;i++)
	{
		s=s+pool[i];
		if(s>n/2)
		{
			p=i;
			break;
		 } 
	}
	for(int i=1;i<=20001;i++)
	{
		ans=ans+abs(i-p)*pool[i];
	}
	cout<<ans;
	return 0;
}