(;AB[sr]AB[ps]AB[os]AB[or]AB[nq]AB[pq]AB[pp]AB[po]AB[qo]AB[rn]AB[sn]AW[ro]AW[qp]AW[sp]AW[qq]AW[pr]AW[rr]AW[qr]AW[qs]C[Black to kill.]AP[goproblems]
(;B[ss];W[rp];B[sq]C[Black 1 and 3 create a bent-four-in-the-corner shape, so White is dead. If 2 at 3, Black 2.RIGHT]LB[rp:2]LB[sq:3])
(;B[rp];W[ss]C[Ko]))