N=int(input())
A=list(map(int,input().split()))
B=list(map(int,input().split()))
from decimal import *
getcontext().prec=50
X=[(Decimal(A[i])/Decimal(B[i]),A[i],B[i]) for i in range(N)]
X.sort(reverse=True)
ANS=0
V=1
mod=998244353
for i in range(N):
  ANS=(ANS+V*A[i])%mod
  V=(V*B[i])%mod
print(ANS)