User-agent: *
Disallow: /
User-Agent: MJ12bot
Crawl-Delay: 20
User-Agent: SemrushBot
Crawl-Delay: 20
User-Agent: AhrefsBot
Crawl-Delay: 20 
User-agent: Riddler
Disallow: /
User-agent: BLEXBot
Disallow: /