#include<fstream.h>
int main()
{
	   ifstream in("input.txt");
	   ofstream out("output.txt");

	   int s;
	   in>>s;

       int a[20001];
	   int min=20000;
	   int max=0;

	   for (int i=0; i<20001; i++)   a[i] = 0;	  

       //輸入
	   int y;
	   if (s<100)
	   {
		    for (i=0; i<s; i++)
			{
				in>>y>>y;
				y+=10000;
				a[y]++;
				if (y<min) min=y;
			    if (y>max) max=y;
			}
	   }
	   else
	   {
		    min = 0;
		    max = 20000;
		    for (i=0; i<s; i++)
			{
				in>>y>>y;
				y+=10000;
				a[y]++;			    
			}
	   }


	   //取中位數
	   long count=0;
	   int z = 0;
	   int mids = s/2;
	   for (i=min; i<=max; i++)
	   {
		   if (a[i]>0)   count+=a[i];
		   if (count>mids)
		   {
			   z = i;
			   break;
		   }
	   }


	   //計算最短距離
	   long result=0;
	   for (i=min; i<z; i++)
	   {
		   if (a[i]>0)  result += (z-i)*a[i];
	   }
	   for (i=z; i<=max; i++)
	   {
		   if (a[i]>0)  result += (i-z)*a[i];
	   }

	   out<<result;

       return 0;
}