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
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
The only line of output should contain the required sum of squares of distances between all pairs of points.
Examples
Input
4
1 1
-1 -1
1 -1
-1 1
Output
32
输入格式
输入
输入的第一行包含一个整数 N （1≤N≤100000） - 点数。以下 N 行中的每一条都包含两个整数 X 和 Y （-10000≤X，Y≤10000） - 点的坐标。两个或多个点可能重合。