Problem Statement

$n$ clay figurines are lined up in a row.
You are given $m$ friendships between pairs of figurines. A "good relation" is defined as follows.
・Figurines in a "good relation" are not in a friend-of-a-friend relation.
・A figurine's friends of friends do not include the figurine itself or its friends.
You want to choose 3 figurines and throw them away. However, you will be cursed unless every 2 of the 3 figurines you throw away are in a "good relation". You do not want to be cursed, so you need to choose the 3 figurines carefully. How many such ways of choosing are there?
For example, when the 3 figurines are the 2nd, 4th, and 5th from the left, (2,5,4) and (2,4,5) are not distinguished.

Input

$n \ m$
$a_1 \ b_1$
$a_2 \ b_2$
$\vdots$
$a_m \ b_m$

$3 \leq n \leq 100$, $1 \leq m \leq \dfrac{n(n-1)}{2}$
The $m$ lines from the 3rd line onward indicate that the $a_i$-th figurine from the left and the $b_i$-th figurine are friends ($a_i \neq b_i$). The same friendship may be mentioned multiple times. $1 \leq a_i,b_i \leq n$, and all input values are integers.

Output

Output the number of ways to choose the figurines to throw away on one line.
Print a newline at the end.
Addendum: Part of the output description has been corrected. (2020/8/5-19:00)

Sample

8 12
1 6
1 7
1 8
2 5
2 6
3 5
3 6
4 5
4 8
5 6
5 7
7 8

3

5 2
4 5
3 5

7

8 16
2 5
3 6
4 1
1 5
8 6
7 2
1 7
3 2
5 3
6 4
1 6
8 2
8 1
6 4
1 5
8 1

3