n = int(input()); o = 998244353
a = list(input().split()); b = list(input().split()); c = []
p = [[[0]*34 for _ in range(5)] for _ in range(10)]; p[0][0][0] = 1
for u,v in zip(a,b):
    if v=="X": c.append(int(u))
    elif v[-1]!="X":
        u,v = int(u),int(v)
        for i in range(8,0,-1):
            for j in range(4,u-1,-1):
                for k in range(33,v-1,-1):
                    p[i][j][k] = (p[i][j][k]+p[i-1][j-u][k-v])%o
for u in c: p[9][4][33] = (p[9][4][33]+p[8][4-u][33])%o
print(p[9][4][33]%o)