Q: i buy second hand iphone 5s but the password it's wrong

Hello sanufa,

Thank you for using Apple Support Communities. 

I see you are having difficulties logging into your iPhone because you don't have the iCloud password. This sounds like the previous owner has activation lock still turned on. The following FAQ article will provide more information: https://support.apple.com/en-us/HT201365

Specifically this part:

What if I purchase a device that is still linked to the previous owner's account?

Contact the previous owner as soon as possible and ask them to erase the device and remove it from their account. Learn how to remove a device from a previous owner's account.

Best regards.