(;GM[1]FF[4]CA[UTF-8]AP[CGoban:3]ST[2]
RU[Japanese]SZ[19]KM[0.00]
PB[Black to play]AW[mn][nn][lo][no][lp][op][mq][oq][nr]AB[mm][nm][ln][on][ko][oo][kp][pp][rp][iq][kq][pq][rq]C[This is the problem position. Black to play and
white has to try and save all stones.]VW[]
;B[np]LB[mo:A][lr:B]
(;W[mo]C[If white connects then all the stones are doomed,]
;B[lq]
;W[mp]
(;B[or]C[this is wrong]
;W[nq]
;B[pr]
;W[lr]
;B[ns]
;W[ms]
;B[os]C[False eye.]
;W[kr]
;B[jr]
;W[ks]C[Real eye!])
(;B[ns]C[This is the tesuji - white now cannot live.]
(;W[os]
;B[pr]
(;W[lr]
;B[or]
;W[nq]
;B[ms])
(;W[ms]
;B[lr]))
(;W[lr]
;B[or]
;W[nq]
;B[ms]
;W[pr]
;B[os]
;W[ps]
;B[qr])
(;W[pr]
;B[mr]
;W[nq]
;B[os]
;W[lr]
;B[ms]
;W[ls]
;B[kr]))
(;B[ls]C[This could be possible but is not]
;W[pr]
;B[qr]
;W[os]
;B[mr]
;W[nq]C[ko
]))
(;W[lr]LB[kr:B][or:A]C[In a tsumego problem white is supposed to save
everything, but would better play this way.
Blacks strongest moves are A and B,
but white can always give up the three stones
at the top and live with the rest.

]
(;B[or]
;W[nq]
;B[mo]
;W[pr])
(;B[kr]
;W[pr]
;B[qr]
;W[os]
(;B[ms]
;W[ls])
(;B[mo]
;W[ms]
;B[nq]
;W[or]
;B[lq]))
(;B[pr]
;W[kr]
;B[jr]
;W[ms]
(;B[mp]
;W[ks]
;B[lq]
;W[nq]
;B[mo])
(;B[mo]
;W[ks]
(;B[nq]
;W[lq]
;B[or])
(;B[lq]
;W[mp]))
(;B[ks]
;W[mo]
;B[lq]
;W[mp]))
(;B[ks]
;W[pr]
;B[qr]
;W[os]
(;B[ms]
;W[ls])
(;B[mo]
;W[ms]
;B[nq]
;W[lq]))
(;B[ms]
;W[pr]
;B[qr]
;W[os])
(;B[lq]
;W[pr]
;B[qr]
;W[os]
;B[ms]
;W[nq]
;B[mo]
;W[ls])
(;B[ps]
;W[kr]
;B[jr]
;W[ms]
(;B[or]
;W[nq]
;B[mo]
;W[ks]
;B[lq]
;W[ns])
(;B[os]
;W[ks]
;B[mo]))))
