Description

You are given N points on a plane. Write a program which will find the sum of squares of distances between all pairs of points.

Input

For each test case, the first line of input contains one integer number N (1≤N≤100000) — the number of points. Each of the following N lines contain two integer numbers X and Y (-10000≤X,Y≤10000) — the coordinates of points. Two or more points may coincide.

Output

One line of output should contain the required sum of squares of distances between all pairs of points.

Sample

Input

4
1 1
-1 -1
1 -1
-1 1

Output

32

Source: daimin