In the “Ready Bitwise” problem, the answer is to be calculated as

P⋅Q−1P⋅Q−1 modulo 998,244,353

where,

Q is coprime with 998,244,353

What is meant by computing a value modulo with a sequence as above? Also, in the second statement, is Q supposed to be coprime with respect to the whole sequence altogether or should they be pairwise coprime?