/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Main
{
	public static void main (String[] args) throws java.lang.Exception
	{
		// your code goes here
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int[][] arr = new int[n][2];
		int[] diff = new int[n];
		long sum = 0;
		for(int i=0;i<n;i++){
			arr[i][0] = sc.nextInt();
			arr[i][1] = sc.nextInt();
			sum += arr[i][1]*n-arr[i][0];
			diff[i] = arr[i][0] - arr[i][1];
		}
		Arrays.sort(diff);
		long res = 0;
		for(int j=n;j>=1;j--){
			res += diff[n-j]*j;
		}
		System.out.println(res+sum);
 
	}
}

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10
5 10
12 4
31 45
20 55
30 17
29 30
41 32
7 1
5 5
3 15