题目描述
Problem Statement
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 = y_i.
Similarly, among the lines parallel to the y axis, the i-th from the left is represented by x = x_i.
For every rectangle that is formed by these lines, find its area, and print the total area modulo 10^9+7.
That is, for every quadruple $(i,j,k,l) satisfying 1\leq i < j\leq n$ and $1\leq k < l\leq m,$ find the area of the rectangle formed by the lines x=x_i, x=x_j, y=y_k and y=y_l, and print the sum of these areas modulo 10^9+7.
Input
Input is given from Standard Input in the following format:
n m
x_1 x_2 ... x_n
y_1 y_2 ... y_m
Output
Print the total area of the rectangles, modulo 10^9+7.
Constraints
- $2 \leq n,m \leq 10^5$
- -$10^9 \leq x_1 < ... < x_n \leq 10^9$
- -$10^9 \leq y_1 < ... < y_m \leq 10^9$
- x_i and y_i are integers.
Sample Input 1
3 3
1 3 4
1 3 6
Sample Output 1
60
The following figure illustrates this input:
The total area of the nine rectangles A, B, ..., I shown in the following figure, is 60.
Sample Input 2
6 5
-790013317 -192321079 95834122 418379342 586260100 802780784
-253230108 193944314 363756450 712662868 735867677
Sample Output 2
835067060
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分