Spy competitor PPC Ads

Hi guys, i would like to know if you know any free tools or website that can help us track competitor PPC ads, specifically on Adwords.

I know SemRush and SPyfu, but those are not free and we have to upgrade and pay to use them entirely.

My main goal is to know what is the exact Keyword my competitor are using and how much they are paying for it.

Thanks in advance!