Problem:
Score : 500 points

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.

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.

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.

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

Solution in Python (3.4.3) (judge verdict: Wrong Answer)

n,m=map(int,input().split())
x=list(map(int,input().split()))
y=list(map(int,input().split()))

X=[]
for i in range(1,n):
    X.append(x[i]-x[i-1])
    
Y=[]
for j in range(1,m):
    Y.append(y[j]-y[j-1])

X1=[len(X) for i in range(len(X))]
for k in range(1,int(len(X)/2)+1):
    X1[k]=X1[k-1]+(len(X)-2*k)
    X1[len(X)-k-1]=X1[k-1]+(len(X)-2*k)
#print(X1)
    
Y1=[len(Y) for i in range(len(Y))]
for l in range(1,int(len(Y)/2)):
    Y1[l]=Y1[l-1]+(len(Y)-2*l)
    Y1[len(Y)-l-1]=Y1[l-1]+(len(Y)-2*l)
#print(Y1)

i=0
j=0
X2=[]
for i in range(len(X1)):
    X2.append(X[i]*X1[i])
Y2=[]
for j in range(len(Y1)):
    Y2.append(Y[j]*Y1[j])
    
print(sum(X2)%(10**9+7)*sum(Y2)%(10**9+7))