(;AP[goproblems]AB[pd]AB[qd]AB[rd]AB[rf]AB[oc]AB[nc]AB[mc]AB[mb]AB[ma]AB[na]AW[nb]AW[ob]AW[pa]AW[qb]AW[pc]AW[qc]AW[rc]C[Try to kill white.FORCE](;B[oa];W[ra]C[If black plays atari at 1 white lives at 2. if black takes the to stones, white will take blacks stone in a snapback.])(;B[ra]LB[oa:A]LB[qa:B]C[Black 1 is on a pivot and kills white because A and B are miai.RIGHT])(;B[sc];W[sb](;B[ra];W[oa](;B[qa]C[RIGHT])(;B[sd];W[qa])(;B[rb];W[sd]))(;B[sd];W[ra])(;B[oa];W[ra])(;B[rb];W[ra]))(;B[sb];W[sc](;B[ra];W[rb](;B[oa];W[sa])(;B[sd];W[oa]))(;B[oa];W[ra];B[pb];W[ob]))(;B[qa];W[ra])(;B[rb];W[ra];B[sb];W[sc])(;B[sa];W[ra];B[sb];W[sc])(;B[sd];W[ra]))