输入描述:

The first line of input contains one integer number N (1 ≤ N ≤ 100 000) — the number of points. Each of the following N lines contain two integer numbers X and Y ( - 10 000 ≤ X, Y ≤ 10 000) — the coordinates of points. Two or more points may coincide.

输出描述:

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

4<br />1 1<br />-1 -1<br />1 -1<br />-1 1<br />

32<br />