(;
GM[1]
SZ[19]
AW[dd][jd][nc][dp][dn][qm][po][qp][qq]
AB[pd][pf][qk][pq][fq][jp][np][qr][rr]
LB[qm:1]
TR[qk]
C[Problem 19. Black to play.  

This time Black has played the low Chinese opening. How should Black continue after White 1 ? ]
(;B[nn]
TE[2]
C[Correct Answer.  

Jumping to 1 is Black's best move. ]
;W[om]
C[White will jump out into the center with 2, but ... ]
;B[on]
C[... Black will harass White by forcing with 3 ... ]
;W[pn];B[pl]
C[... and peeping at 5. <= ]
)
(;B[ok]
C[Failure.  

Black 1 doesn't put much pressure on White. ]
;W[rk]
C[White will play 2 ... ]
;B[rj];W[rl]
C[... and 4, easily securing a base for her stones on the right side. <= ]
)
)