n = int(input())
s = input()

MOD = 998244353

if n % 10 != 0:
    print(0)
    exit(0)

n2 = n // 10

dp = [0] * (n2 + 1)
dp[0] = 1

for i in range(n2):
    if dp[i] == 0:
        continue

    dp[i] %= MOD

    i10 = i * 10
    
    for k in range(1, n2 - i + 1):
        if s[i10 + 2 * k] == 'o' and s[i10 + 5 * k] == 'o' and s[i10 + 10 * k] == 'o':
            dp[i + k] += dp[i]

print(dp[n2] % MOD)