System.out.println("请输入整数:");
Scanner scan = new Scanner(System.in);
int num = scan.nextInt();
if(num<0||num>100){
System.out.println("数据录入有误");
}else if (num<=60){
System.out.println("不合格");
}else if (num<=70){
System.out.println("合格");
}else if(num<=80){
System.out.println("中");
}else if (num<=90){
System.out.println("良");
}else{
System.out.println("优秀");
}