from functools import cmp_to_key
def cmp(x, y):
    a, b = x
    aa, bb = y
    s = a*(bb-1) - aa*(b-1)
    return 1 if s > 0 else -1 if s < 0 else 0

N = int(input())
A = list(map(int,input().split()))
B = list(map(int,input().split()))
mod = 10**9 + 7
C = [(A[i],B[i]) for i in range(N)]
C.sort(key = cmp_to_key(cmp))
x = 1
ans = 0
for a,b in C:
  ans += a*x
  ans %= mod
  x *= b
  x %= mod
print(ans)