import sys
input = lambda :sys.stdin.readline()[:-1]
ni = lambda :int(input())
na = lambda :list(map(int,input().split()))
yes = lambda :print("yes");Yes = lambda :print("Yes");YES = lambda : print("YES")
no = lambda :print("no");No = lambda :print("No");NO = lambda : print("NO")
#######################################################################


n = ni()
mod = 998244353

print(n * (n - 1) * (n - 2) * (n - 3) // 24 * pow(26, n - 4, mod) % mod)