mod=998244353

n=int(input())

dp=[0]*(n+1)
dp[0]=1
for i in range(n):
  ndp=[0]*(n+1)
  for j in range(n):
    ndp[j]+=dp[j]*25
    ndp[j+1]+=dp[j]
  dp=[i%mod for i in ndp]

ans=0
for i in range(n+1):
  ans+=dp[i]*(i//3)
print(ans%mod)