MOD = 998244353


def comb(n: int, k: int):
    if k < 0 or n < k:
        return 0
    p = 1
    q = 1
    for i in range(k):
        p = p * (n - i) % MOD
        q = q * (i + 1) % MOD
    return p * pow(q, -1, MOD) % MOD


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