CF76E.Points

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.

给你平面上的 $N$ 个点。请编写一个程序，计算所有点对之间距离的平方和。

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.

输入的第一行包含一个整数 $N$（$1 \leq N \leq 100\,000$）—— 点的数量。接下来的 $N$ 行，每行包含两个整数 $X$ 和 $Y$（$-10\,000 \leq X, Y \leq 10\,000$）—— 各点的坐标。两个或更多点可能重合。

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

输出仅包含所有点对之间距离的平方和。