/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
		int[] arr = {2,3,4,1,1,2,4};
		findOdd(arr);
	}
	
	public static void findOdd(int[] arr){
		HashMap hm = new HashMap();
		int value=0;
		for(int i=0;i<arr.length;i++){
			value=1;
			if(hm.containsKey(arr[i])){
				value = (Integer) hm.get(arr[i]);
				value++;
			}
			hm.put(arr[i], value);
		}
		
		Iterator it = hm.entrySet().iterator();
		Map.Entry entry=null;
		while(it.hasNext()){
			entry = (Map.Entry)it.next();
			if((Integer)(entry.getValue())%2!=0){
				System.out.println((Integer)entry.getKey() +" has occurred odd no of time");
			}
		}

	}
}