MOD = 998244353
N = int(input())
dp = [0] * (N + 2)
dp[0] = 1
for i in range(N):
    for j in reversed(range(i + 2)):
        dp[j] = 25 * dp[j] + dp[j - 1]
        dp[j] %= MOD
ans = 0
for i in range(N+1):
    ans += dp[i] * (i//3)
    ans %= MOD
print(ans)