Puzzle #4 PBC

PBC is a unique event in RS Club that is Puzzle Battle Championship. It has over 15 contestants participating for 5 positions with exciting prizes.

Today is the fourth puzzle of PBC. Private message me the answer only (STRICT RULE). No more warnings if you put the answer and even if they don't copy you.

Difficulty: HARD. White to play and draw. Send me the full continuation until a stalemate occurs

Ans: Stay with the king on a1. Repeat ka1, kb2 or ka2 or kb1