from copy import deepcopy
MOD = 998244353

N = int(input())
A = list(map(int, input().split()))
B = input().split()
X = []
Y = []
for i in range(N):
    if B[i].isdigit():
        Y.append((A[i], int(B[i])))
    elif B[i] == 'X':
        X.append((A[i], 0))

DP = [[[0 for b in range(34)] for a in range(5)] for i in range(9)]
DP[0][0][0] = 1
for u, d in Y:
    dp = deepcopy(DP)
    for i in range(len(DP)):
        for j in range(len(DP[i])):
            for k in range(len(DP[i][j])):
                if i >= 1 and j >= u and k >= d:
                    dp[i][j][k] = (DP[i][j][k]+DP[i-1][j-u][k-d]) % MOD
    DP = deepcopy(dp)
DP9 = [[0 for b in range(34)] for a in range(5)]
for u, d in X:
    dp9 = deepcopy(DP9)
    for j in range(len(DP9)):
        for k in range(len(DP9[j])):
            if j >= u and k >= d:
                dp9[j][k] = (DP9[j][k]+DP[8][j-u][k-d]) % MOD
    DP9 = deepcopy(dp9)
print(DP9[4][33])