(;GM[1]FF[4]SZ[19]
GN[Invasion is possible]
PC[http://senseis.xmp.net/?CountingLesson1]AP[GoWiki:2009]
DT[2009-08-18]
C[Diagram from http://senseis.xmp.net/?CountingLesson1

Invasion is possible]
PL[W]

AB[nc][qd]
AW[qf]

;W[qc]C[W1]MN[1]
;B[pd]C[B2]MN[2]
;W[rd]C[W3]MN[3]
;B[re]C[B4]MN[4]
;W[rc]C[W5]MN[5]
;B[qe]C[B6]MN[6]
;W[ob]C[W7]MN[7]

;
)
