Achievement: Solve a 4d problem

Solve a 4d problem

700 XP

Solve a 4d problem.

Recently completed by

Mattimite 2k, minkahoshi 2k, Dmitry Savin 3k, albdoma 3d, Lukáš Rak 1k, Pyv 1k, Kruxo 4k, Matouš Babka 1d, Bibi 3k, Никита Горохов 1k

and 548 others.