题解 | #杨辉三角的变形#

import java.util.Scanner;

public class Main {
	

	public static void main(String[] args) throws Exception {
		
		Scanner sc = new Scanner(System.in);
		int line = 0;
		int a = 0;
		
		while(true){
			if(sc.hasNextInt()){
				
				line = sc.nextInt();
				if(line > 0){
					switch(line){
					case 1:
					case 2:System.out.println("-1");break;
					default: {
						a = line - 2;
						a = a%4;
						switch(a){
						 case 0: System.out.println("4");break;
						 case 1: 
						 case 3: System.out.println("2");break;
						 case 2: System.out.println("3");break;
						 
						}
					}
					}
				}else System.out.println("不是正整数");

			}else break;
			
			
			
			
		}
		sc.close();			
		
	}
	
	
	
}