import java.util.*; public class Main{ public static void main(String [] args){ Scanner sc = new Scanner(System.in); while(sc.hasNextInt()){ int num = sc.nextInt(); if(num == 1 || num == 2){ System.out.println(-1); }else if(num % 4 == 0){ System.out.println(3); }else if(num % 4 == 1 || num % 4 == 3){ System.out.println(2); }else{ System.out.println(4); } } } }