n = int(input())
mod = 998244353

fact = [1] * (n + 1)
inv = [1] * (n + 1)
finv = [1] * (n + 1)
for i in range(2, n + 1):
    fact[i] = fact[i - 1] * i % mod
    inv[i] = mod - inv[mod % i] * (mod // i) % mod
    finv[i] = finv[i - 1] * inv[i] % mod
def comb(x, y):
    return fact[x] * finv[y] % mod * finv[x - y] % mod

P = [1]
for i in range(n):
    P.append(P[-1] * 25 % mod)

ans = 0
for i in range(n + 1):
    res = comb(n, i)
    res *= P[n - i]
    res %= mod
    res *= (i // 3) % mod
    res %= mod
    ans += res
    ans %= mod
print(ans)