(;GM[1]FF[4]SZ[19]
GN[Solution]
PC[http://senseis.xmp.net/?SnapbackProblem20/Solution]AP[GoWiki:2009]
DT[2009-04-22]
C[Diagram from http://senseis.xmp.net/?SnapbackProblem20/Solution

Solution]
PL[W]

AB[nb][ob][rb][nc][pc][qc][qd][rd][sd][se]
AW[pb][qb][oc][rc][od][pe][qe][re][rf][sf]
CR[rb]

;W[sb]C[W1]MN[1]
;B[sc]C[B2]MN[2]
;W[ra]C[W3]MN[3]
;B[sa]C[B4]MN[4]

;CR[rb]
)
