corejava-programming: Program to provide the count of absentees and swipe defaulters

import java.util.Scanner;

public class DefaulterCounter{
public static void main(String[] args) throws Exception{
Scanner input=new Scanner(System.in);
int n=Integer.valueOf(input.nextLine().trim());
if(1<=n && n<=500){
String[] inTime=new String[n];
String[] outTime=new String[n];
String[] entity;
String[] entity1;
int index;
int defaulters=0;
int absentees=0;
int count=0;
int hh=0;
int mm=0;
String line;
while(!(line=input.nextLine().trim()).equalsIgnoreCase("0")){
entity = line.split(" ");
index=Integer.valueOf(entity[0])-1;
if(inTime[index]==null){
inTime[index]= entity[1];
count++;
}
else{
outTime[index]= entity[1];
entity=outTime[index].split(":");
entity1=inTime[index].split(":");
hh=Integer.valueOf(entity[0])-Integer.valueOf(entity1[0]);
mm=Integer.valueOf(entity[1])-Integer.valueOf(entity1[1]);
if(hh<9 || (hh==9 && mm<0))
defaulters++;
}
}
absentees=n-count;
System.out.println(absentees);
System.out.println(defaulters);
}else{
throw new Exception("Invalid Auguments!");
}
}
}