//输出*矩形
        
        char sp=' ';
        char ff='*';
        
        for (int i = 1; i <= 200; i++) {
            if(i%2!=0){
                System.out.print(ff);
            }else{
                System.out.print(sp);
            }
            if(i%20==0){
                System.out.println();
            }
                
        }