输入两个字符串并判断是哪种情况

//输入两个字符串并判断是哪种情况
Scanner s=new Scanner(System.in);
String a=s.nextLine();
String b=s.nextLine();
if (a.length()!=b.length()) {
System.out.println(1);

	}
	if (a.equals(b)) {
		System.out.println(2);
	}
	if (a.toLowerCase().equals(b.toLowerCase())&&!a.equals(b)) {
		System.out.println(3);
	}
	if (a.length()==b.length()&&!a.toUpperCase().equals(b.toUpperCase())) {
		System.out.println(4);
		
	}