n = int(input())
dp = [0] * (n+1)
dp[0] = 1
mod = 998244353 
for i in range(n):
    n_dp = [0] * (n+1) 
    for j in range(n):
        n_dp[j] += dp[j] * 25
        n_dp[j+1] += dp[j]
        n_dp[j] %= mod
        n_dp[j+1] %= mod
#     print(n_dp)
    dp = n_dp
ans = 0
for i in range(n+1):
    ans += dp[i] * (i//3)
    ans %= mod
print(ans)