It's cubic version of task Not easy: pCcdKz_rK_p_bTBF_PXywP_QfaH
pCcdKz_rK_p_bTBF_PXywP_QfaH
Alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_, flag format: spbctf_some_words
ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_