N = int(input()) + 1
A = [int(input()) for i in range(N)]
B = [int(input()) for i in range(N)]

ans = 0
MOD = 10**9 + 7

b = sum(B)
for i in range(N-1,-1,-1) :
    ans += a*b
    ans %= MOD
    b -= B[i]
print(ans)