(;GM[1]FF[4]CA[UTF-8]AP[CGoban:2]ST[2]
RU[Japanese]SZ[7]KM[0.00]
AW[eb][fb][gb][dc][ec][bd][cd][dd][ae][be][cf][df]AB[bb][cb][db][ac][bc][fc][gc][ad][ed][fd][ef][ff]C[Black to win the game.]
(;B[da]
(;W[ea]C[CHOICE]
(;B[ba]
;W[ee]
;B[fe]
;W[de]
;B[dg]
;W[cg]
;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.])
(;B[aa]
;W[ee]
;B[fe]
;W[de]
;B[dg]
;W[cg]
;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.])
(;B[de]
;W[ba]
;B[aa]
;W[ab]LB[ca:A]C[Black has no ko threat, and he can not play at A.])
(;B[dg]
;W[ba]
;B[aa]
;W[ab]LB[ca:A]C[Black has no ko threat, and he can not play at A.]))
(;W[ba]C[CHOICE]
;B[aa]
;W[ab]
;B[ca]
;W[ea]
;B[aa]
;W[ee]
;B[fe]
;W[de]
;B[dg]
;W[cg]
;B[eg]C[RIGHT Correct. Now you can try ferdi's original problem and learn from the difference.]))
(;B[aa]
;W[da]
;B[ca]
;W[ea]C[The best black can get from here is jigo.])
(;B[ea]
;W[da]C[Black is dead.])
(;B[de]
;W[da]C[Black is dead.])
(;B[dg]
;W[da]C[Black is dead.]))