By fernandoylet on Skatehive
White plays and wins in 5 moves https://lichess.org/xrpLYEKC Re2+ Kf3 2. Qe4+ Kg3 3. Re3+ Kf2 4. Qf4+ Kg2 5. Qf3# The analysis board does checkmate in 5 moves Rc3+ Kd2 2. Qd3+ Ke1 3. Rc1+ Kf2 4. Rc2+ Ke1 5. Qe2# Source: This publication is in my collection "500 chess puzzles. Mate in 5. Advanced & Expert Level."