Achievement: Solve 10 4d problems

Solve 10 4d problems

1400 XP

Solve 10 4d problems.

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jaokhun 2k, Korablik 1d, schnirz 1k, Ярик1111 3k, x0000 3d, JohnSmithGo 2d, Daviid 6d, salu 1k, Patrick361 1k, dejawu 5d

and 94 others.