Squares in a graph P99912

You are given an undirected graph $G$. Let us define a square as any cycle of length exactly four in $G$. Can you count the number of squares in $G$?

Input

Input consists of several cases. Every case begins with two natural numbers $n$ and $m$, which are respectively the number of vertices and the number of edges of $G$. Follow $m$ pairs $x$ $y$ to indicate that there is an edge connecting vertices $x$ and $y$. Assume $0 \le n \le 2000$ and $0 \le m \le 10n$. Vertices are numbered starting at 0. There are no edges of the kind $x$ $x$, nor repeated edges.

Output

For every given $G$, print its number of squares.