AOJ 0384 Dudeney Number

Solved Users (link to submissions)
abcdematukiyo
atjh16
beet
c64qh33
c7c7
clavis1107
ei1333
Empress
endered
face4
gondust
hamayanhamayan
imulan
isp
Kaz_nl
kmcyuma
ktnsmh
kuwaaaaaaaaaaaaaaaaa
Lafolia
lafson
masa002
naoto172
nii
polyomino
ranomani13
Ryoma_1208
sakasu1
sayachang
SHIN1105K
suibaka
TKT29
ume10
vjudge2
vjudge3
vjudge5
whalefromegg
WUonsite
yamamayumi9489
yebisu
yebityon
yudedako