Problem1557--Points

1557: Points

Time Limit: 2 Sec  Memory Limit: 256 MB
Submit: 0  Solved: 0
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Description

time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

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

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