import sys
readline = sys.stdin.readline

N = int(readline())
mod = 998244353
S = []
for i in range(N):
    s = readline().rstrip()
    S.extend(list(s))

N *= 16
dp0 = [0] * N
dp1 = [0] * N
dp2 = [0] * N
if S[0] == "d":
    dp1[0] = 1
elif S[0] == "k":
    dp2[0] = 1
else:
    dp0[0] = 1
    dp1[0] = 1
    dp2[0] = 1

for i in range(1, N):
    if S[i] == ".":
        if i % 2:
            dp0[i] += dp0[i - 1] + dp1[i - 1] + dp2[i - 1]
            dp1[i] += dp2[i - 1] + dp1[i - 1]
            dp2[i] += dp1[i - 1] + dp2[i - 1]

        else:
            dp0[i] += dp0[i - 1]
            dp1[i] += dp2[i - 1] + dp0[i - 1] + dp1[i - 1]
            dp2[i] += dp1[i - 1] + dp0[i - 1] + dp2[i - 1]

    elif S[i] == "d":
        if i % 2 == 0:
            dp1[i] += dp0[i - 1] + dp1[i - 1] + dp2[i - 1]
            if S[i - 1] == ".":
                dp1[i] -= dp1[i - 1]
        else:
            dp1[i] += dp1[i - 1] + dp2[i - 1]
            if S[i - 1] == ".":
                dp1[i] -= dp1[i - 1]
    else:
        if i % 2 == 0:
            dp2[i] += dp0[i - 1] + dp1[i - 1] + dp2[i - 1]
            if S[i - 1] == ".":
                dp2[i] -= dp2[i - 1]
        else:
            dp2[i] += dp1[i - 1] + dp2[i - 1]
            if S[i - 1] == ".":
                dp2[i] -= dp2[i - 1]
    dp0[i] %= mod
    dp1[i] %= mod
    dp2[i] %= mod
    
print( (dp0[-1] + dp1[-1] + dp2[-1] ) % mod )