(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[4]KM[0.00]
PW[Weiß]PB[Schwarz]AW[aa][ca][cb][db][dc]AB[bc][cc][bd][cd]C[Black to play - what's the best he can do?]PL[B]
(;B[bb]CR[bb]
(;W[ba]CR[ba]
;B[ab]CR[ab]
;W[ac]CR[ac]C[Now, please capture :)]
;B[ad]CR[ad]C[Seki, Black wins by one point (the prisoner). RIGHT])
(;W[ab]CR[ab]
;B[ba]CR[ba]
;W[ac]CR[ac]
;B[ad]CR[ad]
;W[ab]CR[ab]
;B[dd]CR[dd]C[White is lost.]))
(;B[ab]CR[ab]
;W[bb]CR[bb]
(;B[ba]CR[ba]
;W[ac]CR[ac]C[White wins!])
(;B[ac]CR[ac]
;W[ba]CR[ba]C[Seki & jigo!]))
(;B[ac]CR[ac]
;W[bb]CR[bb]
;B[ab]CR[ab]
;W[ba]CR[ba]C[Seki & jigo.]))