K=int(input())
L=[]
from itertools import product
S='NUPC'
for A in product(range(2),repeat=4):
  ans=''
  for i in range(8):
    if i%2==0:
      ans+=S[i//2]
    else:
      pos=i//2
      if A[pos]==1:
        ans=ans+ans
  L.append(ans)
L.sort()
print(L[K-1])