/* 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){
		int res=0;
		for(int i=0;i<arr.length;i++){
			res= res^arr[i];
		}
		System.out.println(res+" has occurred odd no of time");
	}
}