public static void func(int pos,int[] arr,int[] aux,int n)
    {
        /*
         * pos is current index in the arr
         * arr is array
         * aux is temp array which will store one possible combination.
         * n is size of the array.
         * */



        //if reached at the end, check the summation of differences
        if(pos == n)
        {
            long sum = 0;
            for(int i = 1 ; i < n ; i++)
            {
                //System.out.print("i = " + i + ", arr[i] = " + aux[i] + " ");
                sum += Math.abs(aux[i] - aux[i - 1]);
            }
            //System.out.println();
            //System.out.println("sum = " + sum);
            if(sum > max)
            {
                max = sum;
            }
            return;
        }

        //else try every combination possible.
        for(int i = 1 ; i <= arr[pos] ; i++)
        {
            aux[pos] = i;
            func(pos + 1,arr,aux,n);
        }
}