为什么要运行的错误，感叹号也是用的中文啊

public class HelloWorld{public static void main(String[] args){int num = 999;int count = 0;    if(num>=0&&num<=999999999){        while(num!=0){            count++;            num/=10;                    }    System.out.println("它是个"+count+"位的数！")；                }else{        System.out.println("输入有误！");    }    }}