N=int(input())
mod=998244353
dp=[0]*(N+10)
dp[0]=1
for i in range(N):
  ndp=[0]*(N+2)
  for j in range(i+2):
    ndp[j]=25*dp[j]+dp[j-1]
    ndp[j]%=mod
  dp=ndp
ans=0
for i in range(N+1):
  ans += dp[i] * (i//3)
  ans%=mod
print(ans)