K=int(input())
prime=[True for _ in range(1000001)]
prime[0]=False
prime[1]=False

ansp=[]

for i in range(2,999999):
  if prime[i]:
    cnt=2
    while i*cnt<1000001:
      prime[i*cnt]=False
      cnt+=1
    if i<999999 and prime[i+2]:
      ansp.append(i)
    if len(ansp)>250:
      break

ans2=0
ansprime=0
for i in range(1,250):
  for j in range(1,250):
    if i*j==K and i+j<=250:
      ans2=i
      ansprime=j
ans=[2]*ans2+ansp[:ansprime]

if K==0:
  print(1)
  print(2)
else:
  print(len(ans))
  print(*ans)