n=int(input())
a=list(map(int,input().split()))
b=input().split()
c1=[]
c2=[]
for i in range(n):
  if "X" not in b[i]:
    c1+=[(a[i],int(b[i]))]
  elif b[i]=="X":
    c2+=[(a[i],0)]
M=998244353
p1=4
p2=33
K=9
q=[[[0]*(p2+1) for i in range(p1+1)] for k in range(K)]
q[0][0][0]=1
for a,b in c1:
  for k in reversed(range(K-1)):
    for i in range(p1+1):
      for j in range(p2+1):
        if i+a<=p1 and j+b<=p2:
          q[k+1][i+a][j+b]+=q[k][i][j]
          q[k+1][i+a][j+b]%=M
ans=0
for a,b in c2:
  if a<=p1:
    ans+=q[K-1][p1-a][p2]
    ans%=M
print(ans)