How to add ScrollView in Android XML?

I am making an Image Gallery, I want to Scroll the Entire Layout, So what should i add in this code, and where should i add those things ? I am making an Image Gallery, I want to Scroll the Entire Layout, So what should i add in this code, and where should i add those things ?

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://ift.tt/nIICcg"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="5sp"
     >


<LinearLayout
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
     >
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView1"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall1" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView2"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall2" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView3"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall3" />
    </LinearLayout>  


<LinearLayout
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
     >
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView4"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall4" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView5"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall5" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView6"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall6" />
    </LinearLayout> 

<LinearLayout
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
     >
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView7"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall7" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView8"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall8" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView9"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall9" />
    </LinearLayout> 

<LinearLayout
    android:gravity="center"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
     >
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView10"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall10" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView11"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall11" />
    <ImageView
        android:padding="10dp"
        android:id="@+id/imageView12"
        android:layout_width="82dp"
        android:layout_height="123dp"
        android:src="@drawable/wall12" />
    </LinearLayout> 

</LinearLayout>