find Uncommon element in Secod arrays
<pre><code>int[] arr1 = { 5, 4, 3, 2, 1 };
        int[] arr2 = { 1, 2, 4, 5 };

        for (int i = 0; i &lt; arr1.Length; i++)
        {
            for (int j = 0; j &lt; arr2.Length; j++)
            {
                if (arr1[i] == arr2[j])
                {
                    //Console.Write(arr1[i]);
                }

            }
        }
</code></pre>

<p>Output of above code:</p>

<p>5,4,2,1</p>

<p>I want output:</p>

<p>3</p>
