LIMIT = 10**6
MOD = 998244353

fac = [1] * LIMIT
for i in range(1, LIMIT):
    fac[i] = fac[i - 1] * i % MOD


def comb(n, r):
    return fac[n] * pow(fac[n - r], -1, MOD) % MOD * pow(fac[r], -1, MOD) % MOD


N = int(input())
ans = comb(N, 4)
ans *= pow(26, N - 4, MOD)
ans %= MOD

print(ans)