System.out.println("请输入年份：");
        Scanner sc=new Scanner(System.in);
        String ss=sc.nextLine();
        int year=Integer.parseInt(ss);
        if(year%400==0 || (year%4==0 && year%100!=0)){
            System.out.println(year+"年是闰年");
        }else{
            System.out.println(year+"年是平年");
        }

Scanner sex=new Scanner(System.in);
        System.out.println(" 请输入性别：");
        String se=sex.nextLine();
        
            
        if(se.equals("男")){
            
            System.out.println(" 请输入身高：");
            String he=sex.nextLine();
            int sg=Integer.parseInt(he);
            
            System.out.println(" 请输入体重：");
            String we=sex.nextLine();
            int tz=Integer.parseInt(we);
            
            int bz = sg-100;
            if(bz-tz>=-3 && bz-tz<=3){
                System.out.println("正常");    
            }else{
                System.out.println("不正常");
            }
            
        }else if(se.equals("女")){
            
            System.out.println(" 请输入身高：");
            String he=sex.nextLine();
            int sg=Integer.parseInt(he);
            
            System.out.println(" 请输入体重：");
            String we=sex.nextLine();
            int tz=Integer.parseInt(we);
            
            int bz = sg-110;
            if(bz-tz>=-2 && bz-tz<=2){
                System.out.println("正常");    
            }else{
                System.out.println("不正常");
            }
            
        }else{
            System.out.println("你走开！");
        }

System.out.println("其输入三个数：");
        Scanner v=new Scanner(System.in);
        String a=v.nextLine();
        int a1=Integer.parseInt(a);
        
        String b=v.nextLine();
        int b1=Integer.parseInt(b);
        
        String c=v.nextLine();
        int c1=Integer.parseInt(c);
        
        int big;
        if(a1>b1){
            big=a1;
            if(a1>c1){
                big=a1;
                System.out.println(big);
            }else{
                big=c1;
                System.out.println(big);
            }
        }else{
            big=b1;
            if(b1>c1){
                big=b1;
                System.out.println(big);
            }else{
                big=c1;
                System.out.println(big);
            }
        }

Scanner scan=new Scanner(System.in);
        System.out.println("请输入用户名：");
        String yhm=scan.nextLine();
        
        System.out.println("请输入密码：");
        String mm=scan.nextLine();
        
        if(yhm.equals("admin")){
            
            if(mm.equals("admin")){
                
                System.out.println("恭喜您登陆成功");
                
            }else{
                
                System.out.println("对不起您输入的密码不正确");
                
            }
            
        }else{
            
            System.out.println("对不起您输入的用户名不正确");
            if(mm.equals("admin")){
                
                
                
            }else{
                
                System.out.println("对不起您输入的密码不正确");
                
            }
        }