what is the cost?
Re: what is the cost?
How much AdWords "costs" depends on what you set for your advertising budget. You control your own costs.
You cannot pay to place a website in the "top 5." Ads can earn high positioning through a combination of quality, performance, and bidding.
I would strongly recommend that you review the material in the AdWords Help Center before you start spending money on advertising. It's necessary to have an understanding of the program--how it works, what it does, what it cannot do, etc.--in order to advertise successfully.
P.S. If the "top 5" refers to your desire to have your website's organic (unpaid) listing show up high on the SERPs (search results page), then that, again, is not something you can pay for.
Getting a high placement on the SERPs can be a long, slow process. That process is called Search Engine Optimization--it is a very wide field and not something we deal with here on the AdWords Community.
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