(;GM[1]FF[4]SZ[19]
GN[Black to make thickness]
PC[http://senseis.xmp.net/?ThicknessExercise2/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?ThicknessExercise2/Solution

Black to make thickness]
PL[B]

AB[oc][qd][qg][oi][nj][fk][lk][mk][ok][pk][il][jl][pl][fm][lm][mm][pm][rm][fn][qn][fo][lo][mo][no][oo][fq][gq][iq][jq][nq][oq][pq][hr]
AW[dc][ph][qi][hj][mj][rj][nk][qk][dl][hl][nl][ol][rl][hm][jm][dn][gn][kn][nn][on][pn][ko][po][dp][ip][jp][lp][mp][pp][rp][hq][kq][qq]
CR[il][jl]

;B[mi]C[B1]MN[1]
;W[lj]C[W2]MN[2]
;B[ki]C[B3]MN[3]
;W[kj]C[W4]MN[4]
;B[jj]C[B5]MN[5]
;W[kk]C[W6]MN[6]
;B[kl]C[B7]MN[7]

;CR[il][jl]
)
