9. N=
gets.to_i
counts
=
Array.new(7,0)
STDIN.read.split.map(&:to_i).map{|i|
i%7}.each{|a|
counts[a]
+=
1
}
total
=
0
(0..6).each{|i|
(i..6).each{|j|
(j..6).each{|k|
next
if
(i+j+k)%7
!=
0
c1
=
counts[i]
c2
=
counts[j]
c3
=
counts[k]
c2
-‐=
1
if
i
==
j
c3
-‐=
1
if
k
==
i
c3
-‐=
1
if
k
==
j
pat
=
c1*c2*c3
if
i==j
&&
j==k
pat
/=
6
elsif
i==j
||
i==k
||
j==k
pat
/=
2
end
total
+=
pat
}
}
}
puts
total