from sys import stdin

n = int(stdin.readline().rstrip())
data = [stdin.readline().rstrip() for _ in range(n)]
p = 998244353
s = "".join(data)
n = 16 * n

dp = [[0 for i in range(3)] for i in range(n+1)]
dp[0][0] = 1
if s[0] == "d":
    dp[1][1] = 1
elif s[0] == "k":
    dp[1][2] = 1
else:
    dp[1][0] = 1
    dp[1][1] = 1
    dp[1][2] = 1

for i in range(1,n):
    if i % 2 == 0:
        if s[i] == "d":
            if s[i-1] == ".":
                dp[i+1][1] = (dp[i][0] + dp[i][2]) % p
            else:
                dp[i+1][1] = (dp[i][0] + dp[i][1] + dp[i][2]) % p
        elif s[i] == "k":
            if s[i-1] == ".":
                dp[i+1][2] = (dp[i][0] + dp[i][1]) % p
            else:
                dp[i+1][2] = (dp[i][0] + dp[i][1] + dp[i][2]) % p
        else:
            dp[i+1][0] = dp[i][0]
            dp[i+1][1] = (dp[i][0] + dp[i][1] + dp[i][2]) % p
            dp[i+1][2] = (dp[i][0] + dp[i][1] + dp[i][2]) % p
    else:
        if s[i] == "d":
            if s[i-1] == ".":
                dp[i+1][1] = (dp[i][2]) % p
            else:
                dp[i+1][1] = (dp[i][1] + dp[i][2]) % p
        elif s[i] == "k":
            if s[i-1] == ".":
                dp[i+1][2] = (dp[i][1]) % p
            else:
                dp[i+1][2] = (dp[i][1] + dp[i][2]) % p
        else:
            dp[i+1][0] = (dp[i][0] + dp[i][1] + dp[i][2]) % p
            dp[i+1][1] = (dp[i][1] + dp[i][2]) % p
            dp[i+1][2] = (dp[i][1] + dp[i][2]) % p

ans = (dp[n][0] + dp[n][1] + dp[n][2]) % p
print("{}".format(ans))