package main

import . "fmt"
import . "sort"

func main() {
	var k int
	Scan(&k)
	s:=[]string{""}
	for _,r:=range "NUPC" {
		for i,t:=range s {
			s[i]=t+string(r)
		}
		for _,t:=range s {
			s=append(s,t+t)
		}
	}
	Strings(s)
	Println(s[k-1])
}