activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <Button
        android:id="@+id/first_btn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/first_btn_name" />

    <LinearLayout
        android:id="@+id/layout_first"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#ffffff"
        android:orientation="vertical" />

    <LinearLayout
        android:id="@+id/layout_second"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#ffffff"
        android:orientation="vertical">

        <TextView
            android:id="@+id/countryName_text"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:textSize="50dp" />
    </LinearLayout>

    <LinearLayout
        android:id="@+id/layout_third"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_weight="1"
        android:background="#ffffff"
        android:orientation="vertical" />
</LinearLayout>