How to Hide AffiliateX – Amazon Affiliate Plugin Admin Menus

function plt_hide_affiliatex_menus() {
	//Hide "AffiliateX".
	remove_menu_page('affiliatex_blocks');
	//Hide "AffiliateX → AffiliateX".
	remove_submenu_page('affiliatex_blocks', 'affiliatex_blocks');
	//Hide "AffiliateX → Contact Us".
	remove_submenu_page('affiliatex_blocks', 'affiliatex_blocks-contact');
	//Hide "AffiliateX → Upgrade".
	remove_submenu_page('affiliatex_blocks', 'affiliatex_blocks-pricing');
}

add_action('admin_menu', 'plt_hide_affiliatex_menus', 1000000000);

Where do I put this code?