Duplicate Number from series

Find the duplicate number from series.

This is simple core program , and interview program that were using ArrayList and variable that make series and find duplicate number.
first that were enter value from user in main method and that create method of finding duplicate number.
and that simple print series.

@@@@@@simple example of finding duplicate number from series@@@@@@

package test;

import java.util.ArrayList;
import java.util.Scanner;

public class Duplicatenumber {

   static ArrayList<Integer> inputNum = new ArrayList<Integer>();
/**** Main Method ****/
public static void main(String args[]){
int check=0;
while(true){
Scanner s = new Scanner(System.in);
//ArrayList<Integer> aa = new ArrayList<Integer>();
//entervalues(check);
System.out.print("Enter Number:-");
check = s.nextInt();
duplicate(check);
if(check == 0) {
print();
break;
}
inputNum.add(check);


}

}


/********** entervalues mehtod *********/
/* private static int entervalues(int check) {
// TODO Auto-generated method stub
//int check=0;
Scanner s = new Scanner(System.in);
System.out.print("Enter Number:-");
check = s.nextInt();
return check;
}

*/
/***** for check duplicates number from series***/
private static void duplicate(int check) {
// TODO Auto-generated method stub
int c = check;
for (int i=0; i<inputNum.size(); i++){
       int x = inputNum.get(i);
       if(c == x){
        System.out.println("You't Enter This Number because is already in series");
        System.out.println("If you continue then press -> 00");
        Scanner s = new Scanner(System.in);
        int twozero = s.nextInt();
        if(twozero == 00){
        main(null);
        }
       
        int temp = x;
        System.out.println("Duplicate No from series is->"+temp);
        System.exit(0);
       }
    }



}


/** for print **/
private static void print() {
// TODO Auto-generated method stub
System.out.println(inputNum);

}

}