def main():
    from sys import stdin, setrecursionlimit
    # setrecursionlimit(1000000)
    input = stdin.readline
    def iinput(): return int(input())
    def sinput(): return input().rstrip()
    def i0input(): return int(input()) - 1
    def linput(): return list(input().split())
    def liinput(): return list(map(int, input().split()))
    def miinput(): return map(int, input().split())
    def li0input(): return list(map(lambda x: int(x) - 1, input().split()))
    def mi0input(): return map(lambda x: int(x) - 1, input().split())
    INF = 1000000000000000000
    MOD = 998244353

    N = iinput()
    dp = [[0] * (N + 1) for _ in [0] * (N + 1)]
    dp[0][0] = 1
    for i in range(N):
        for j in range(N):
            dp[i+1][j+1] += dp[i][j] 
            dp[i+1][j+1] %= MOD
            dp[i+1][j] += dp[i][j] * 25
            dp[i+1][j] %= MOD
    
    ans = 0
    for i, d in enumerate(dp[-1]):
        ans += (i // 3) * d
        ans %= MOD
    print(ans)

main()