I'm stuck on one of these @BlackboxPuzzles. Help? #Blackbox 😤◼️ https://t.co/AWfW5tQLLj ◼️📲 https://t.co/4FPB9aWEPC

I'm stuck on one of these @BlackboxPuzzles. Help? #Blackbox 😤◼️https://t.co/AWfW5tQLLj ◼️📲 http://pic.twitter.com/4FPB9aWEPC

— Unai Herrán (@unaiherran) February 26, 2016