(;SZ[19]AB[qb]AB[pb]AB[pc]AB[qd]AB[qe]AB[of]AB[pf]AB[qf]AB[ng]AB[mf]AB[le]AB[kc]AB[jc]AB[hc]AB[id]AB[ib]AB[rb]AW[qc]AW[ob]AW[oc]AW[nc]AW[mc]AW[lc]AW[pd]AW[pe]AW[ne]AW[oe]AW[rc]C[Does white require a move at A to ensure that his group is alive? Otherwise, please play at B.FORCE]LB[kb:A]LB[ig:B]FF[4]GM[1]AP[Jago:Version 4.16]GN[goproblem_x01]
(;W[ig]
(;B[na]
(;W[la]
(;B[oa]
(;W[ma];B[kb]
(;W[lb];B[nb]
(;W[pa];B[qa]
(;W[mb]C[RIGHT])
(;W[sb];B[rd];W[mb]C[RIGHT]))
(;W[mb];B[pa])
(;W[sb];B[pa]))
(;W[nb];B[lb])
(;W[pa];B[lb]))
(;W[kb];B[ma])
(;W[mb];B[kb])
(;W[nb];B[lb]
(;W[kb];B[ja]
(;W[ka];B[ma];W[mb];B[pa])
(;W[ma];B[ka])
(;W[pa];B[ka])
(;W[mb];B[ka]))
(;W[pa];B[kb])
(;W[mb];B[kb]))
(;W[lb];B[pa]))
(;B[kb];W[lb];B[oa];W[ma];B[nb];W[pa]C[RIGHT];B[qa]
(;W[mb]C[RIGHT])
(;W[sb];B[rd];W[mb]C[RIGHT]))
(;B[ma];W[mb];B[kb];W[lb];B[oa];W[pa]C[RIGHT])
(;B[lb];W[kb];B[oa];W[mb];B[ja];W[ka];B[ma];W[pa]C[RIGHT]))
(;W[oa];B[ka]
(;W[ma];B[mb])
(;W[la];B[lb])
(;W[mb];B[ma])
(;W[lb];B[la]))
(;W[lb];B[ma]
(;W[oa];B[la])
(;W[la];B[oa])
(;W[kb];B[oa])
(;W[ka];B[oa]))
(;W[kb];B[ma]
(;W[oa];B[ka]
(;W[ja];B[la])
(;W[lb];B[la]))
(;W[la];B[oa])
(;W[lb];B[oa]))
(;W[ma];B[lb]
(;W[nb];B[oa])
(;W[oa];B[mb])
(;W[kb];B[ka]
(;W[oa];B[mb])
(;W[mb];B[oa]))
(;W[mb];B[oa]))
(;W[mb];B[kb])
(;W[nb];B[lb]))
(;B[lb]C[For explanation, see next problem.]))
(;W[kb]C[There is really no need to play here, white is unconditionally alive.]))