I unblocked a number from Whatsapp without taking a screenshot, now I need the number but I don't have it.

Is there anyway I can get the person's number? I blocked the person, now I need their number to contact them. I unblocked them without thinking that their number will get out of the block list which also means I won't have it anymore. I should've taken a screenshot but that didn't cross my mind. Is there anyway to get it again?