Points

There are n points on the plane. Find the sum of squares of distances between all pairs of points.

Input

The first line contains number of points n (1 ≤ n ≤ 100 000). Each of the next n lines contains two numbers x and y (‑10 000 ≤ x, y ≤ 10 000) – the points coordinates.

Output

Print one integer - the sum of squares of distances between all pairs of points.

Examples