Field
Field
On a two-dimensional plane, there are m lines drawn parallel to the x axis, and n lines drawn parallel to the y axis. Among the lines parallel to the x axis, the i-th from the bottom is represented by y = yi
. Similarly, among the lines parallel to the y axis, the i-th from the left is represented by x = xi
.
For every rectangle that is formed by these lines, find its area, and print the total area modulo 109
+ 7.
That is, for every quadruple (i, j, k, l) satisfying 1 ≤ i< j ≤ n and 1 ≤ k < l ≤ m, find the area of the rectangle formed by the lines x = xi
, x = xj
, y = yk
and y = yl
, and print the sum of these areas modulo 109
+ 7.
Input
The first line contains two integers n and m (2 ≤ n, m ≤ 105
).
The second line contains n integers -109
≤ x1
< x2
< ... < xn
≤ 109
.
The third line contains m integers -109
≤ y1
, y2
, ..., ym
≤ 109
.
Output
Print the total area of the rectangles, modulo 109
+ 7.
Example
The following figure illustrates this input:
The total area of the nine rectangles A, B, ..., I shown in the following figure, is 60.
3 3 1 3 4 1 3 6
60
6 5 -790013317 -192321079 95834122 418379342 586260100 802780784 -253230108 193944314 363756450 712662868 735867677
835067060