(;AB[bb][bd][bi][ca][cc][cd][ch][ci][cj][cl][cm][cp][cr][dc][dg][dk][dp][dr][eb][ec][ed][ee][ef][eg][eh][ei][ek][el][em][eq][fa][fc][fi][fk][fn][fq][gb][gi][gl][gn][gp][gr][hd][he][hf][hg][hi][ho][hq][ib][ic][ie][il][in][ip][ir][jg][jh][ji][jm][jr][kc][ke][kf][ki][kk][kn][lb][ld][le][lj][lk][ll][lm][lo][me][mn][mp][ne][np][nq][ns][od][oe][of][og][ok][oq][or][os][pj][pk][pl][pm][pn][pq][qd][qe][qi][qk][re][rf][rg][rh][rj][si]
AW[ab][ac][ad][af][ag][ai][bc][bf][bh][bk][bm][bp][br][ce][cf][cg][ck][co][cq][dd][de][dh][di][dj][dl][dm][dn][do][ej][eo][fe][ff][fg][fh][fj][fl][fo][gc][gd][gj][hb][hc][hj][id][if][ij][jb][jc][jd][je][jf][jj][jn][jo][jp][jq][kd][kg][kh][kj][ko][kq][kr][lc][lf][li][lp][lr][mb][mc][md][mf][mh][mj][mk][mq][mr][nc][nd][nk][nm][nn][nr][oc][oi][oj][ol][on][oo][op][pc][pf][ph][pi][ps][qc][qf][qg][qh][qq][rb][rd][sc]
LB[yy:1][yy:0][yy:0]TR[qq]PL[B]
C[White tried the marked move. How to
respond?]
(;B[qo]
MN[1]
;W[qr]
;B[rp]
C[RIGHT These are the only moves that
kill White, while retaining the lead.]
)(;B[qp]
;W[rp]
(;B[qo]
;W[qr]
C[White can't be killed unconditionally.]
)(;B[rq]
;W[qo]
;B[pp]
;W[po]
C[Black's loss is too big.]
))(;B[qr]
;W[qo]
;B[qp]
;W[po]
C[Black's loss is too big.]
)(;B[pp]
;W[qr]
(;B[ro]
;W[rp]
;B[qp]
;W[sq]
C[White can't be killed unconditionally.]
)(;B[rp]
;W[qo]
;B[po]
;W[qp]
;B[ro]
;W[rn]
(;B[qn]
;W[rm]
)(;B[rm]
;W[qn]
;B[sn]
;W[so]
;B[sp]
;W[rq]
(;B[sm]
;W[sq]
;B[so]
;W[rs]
)(;B[so]
;W[sq]
;B[sm]
;W[rs]
)))))