(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play]AW[mp][np][lq][nq][pq][qq][lr][nr][qr]AB[mo][no][oo][kp][lp][pp][qp][kq][mq][rq][jr][mr][rr]C[This is the problem position. Black to play]
;B[qs]C[Out of the possible moves it seems the correct move is
this one - death in the hane.]
(;W[ps]C[White clearly cannot block here]
;B[oq]
;W[pr]
;B[or])
(;W[pr]C[So the strongest reply is to draw back.]
;B[ps]
(;W[os]C[This looks likely to be two eyes but...]
;B[oq]C[Black can wedge in here]
;W[rs]
;B[op]
(;W[or]
(;B[qs]C[If black plays the throw in he fails]
;W[ms])
(;B[ms]C[But black can play here making miai of the
throw in and capturing the two white stones on
the left.]
;W[ls]C[Note that if white has a stone here at the start of the problem
he cannot be killed.]
;B[qs]
;W[ns]
;B[mr]C[Capturing three stones is still only one eye.]))
(;W[ms]
;B[or]C[This leaves white with one eye.]))
(;W[or]C[This doesn't work either.]
;B[op]
(;W[os]
;B[ms])
(;W[ms]
;B[os]))
(;W[op]C[Nor this.]
;B[or]
;W[oq]
;B[os])))
