MOD=10**9+7
n=int(input())
a=list(map(int,input().split()))
b=list(map(int,input().split()))
p=[]
for i in range(n):
    p.append(((b[i]-1)/a[i],b[i],a[i]))
p.sort()
p.reverse()
currlev=1
ans=0 
for i in range(n):
  _,b1,a1=p[i]
  ans=(ans+currlev*a1)%MOD
  currlev=(currlev*b1)%MOD
print(ans)