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.
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.
The only line of output should contain the required sum of squares of distances between all pairs of points.
4
1 1
-1 -1
1 -1
-1 1
32