Android Adview Getting Error

I get these errors when placing adview ad. error: Error parsing XML: unbound prefix Copy

So, example

<RelativeLayoutxmlns:android="http://schemas.android.com/apk/res/android"xmlns:ads="http://schemas.android.com/apk/res-auto"android:id="@+id/mainLayout"android:layout_width="match_parent"android:layout_height="match_parent"><com.google.android.gms.ads.AdViewandroid:id="@+id/adView"android:layout_width="match_parent"android:layout_height="wrap_content"android:layout_alignParentBottom="true"android:layout_alignParentLeft="true"ads:adSize="BANNER"ads:adUnitId="@string/ad_unit_id"/></RelativeLayout>