AOJ 1341 Longest Chain

Solved Users (link to submissions)
aizu_a
applejack
asi1024
bal4u
beet
birdstorm
blue_jam
bnuvjudge2
brunoja
camypaper
catupper
chocorusk
climpet
cos
cpp575
DAyama
dohatsu
Dopa
enrevol
fidels
fortoobye321
gxokm
hama_du
hec
hirokazu
hogloid
hongjun7
ichyo
id
issysan
japlj
jin_matakich
kagamiz
koosaga
kopricky
kriii
kyuridenamida
latte0119
logicmachine
lyrically
MarX
math
mohejin
namonakiaccount
naoto172
nisshy
nullmineral
orpheus
pachicobue
paunchy
primenumber
s1190048
satashun
sd0061
sigma425
sky58
snuke
sodabeta
square1001
stqn
sugim48
tempura0224
theguiler
tozangezan
ukuku09
vjudge1
vjudge2
vjudge3
vjudge4
vjudge5
warden
wo
yosupo
zhujiale
zimpha