(;AB[qc]AB[rd]AB[re]AB[qf]AB[qg]AW[qe]AW[oe]AW[og]AW[ng]AW[mg]AW[lg]AB[mf]AB[me]AB[md]AB[mc]AB[nb]AB[ob]AB[oc]AW[nd]AW[nc]AW[mb]AW[lb]AW[kc]AW[ke]TR[mc]TR[md]TR[me]TR[mf]C[How can black save the four marked stones?]AP[goproblems]
(;B[of]
(;W[pf]
(;B[od];W[ne];B[nf];W[pe];B[pg]C[RIGHT])
(;B[ne];W[od]
(;B[pg];W[nf])
(;B[pe];W[nf];B[pd];W[of])
(;B[nf];W[pg]))
(;B[nf]C[];W[pg]
(;B[od];W[pe];B[ne]C[RIGHT])
(;B[pd];W[pe])
(;B[qd];W[pe])))
(;W[nf];B[ne];W[od];B[pf]C[RIGHT]))
(;B[nf];W[of])
(;B[od];W[ne])
(;B[ne];W[od];B[of];W[pf]
(;B[pg];W[nf])
(;B[pe];W[nf];B[pd];W[of])
(;B[nf];W[pg]))
(;B[pe];W[of])
(;B[pf];W[of])
(;B[pd];W[of]))