Black to play (from Go game guru - week 2 easy problem)
(;SZ[19]C[]AW[os]AW[or]AW[pr]AW[qr]AW[qq]AW[rp]AW[sq]AW[sr]AB[oq]AB[nq]AB[pq]AB[nr]AB[ns]AB[qp]AB[qo]AB[ro]AB[so]AB[qs]GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]RU[Japanese]SO[http://gogameguru.com/]
(;B[rs];W[sp];B[rr]C[Well doneRIGHT])
(;B[sp];W[rs]C[White has 2 eyes unconditionally])
(;B[rq];W[sp]C[wrong - 2 eyes for white])
(;B[rr];W[rs];B[ss]C[Ko - black can do better]))