4-Cycle (Easy)

$N$ vertices and $M$ undirected edges form a simple graph $G$. In a simple graph, each pair of vertices is joined by at most $1$ edge, and every edge connects two distinct vertices. The vertices of $G$ are numbered with positive integers at most $N$.

A simple cycle of length $L$ in $G$ is a sequence of vertices $(v_0, v_1, \cdots, v_L)$ that satisfies the following conditions.

• For every $0 \leq i < L$, an edge in $G$ connects $v_i$ and $v_{i+1}$.
• For every $0 \leq i < j < L$, $v_i \neq v_j$, and $v_L = v_0$.

Two simple cycles are regarded as the same cycle if one can be transformed into the other with the following operations.

• Reverse the sequence. That is, change $(v_0, v_1, \cdots, v_L)$ to $(v_L, \cdots, v_1, v_0)$.
• Append the second element to the end and delete the first element. That is, change $(v_0, v_1, \cdots, v_L)$ to $(v_1, \cdots, v_L, v_1)$.

For example, the simple cycles $(1, 2, 3, 4, 1)$ and $(2, 1, 4, 3, 2)$ are the same simple cycle. Count the number of distinct simple cycles of length $4$ in $G$.

The first line contains $N$ ($2 \leq N \leq 1\,000$), the number of vertices of $G$, and $M$ ($1 \leq M \leq 1\,000$), the number of edges, separated by a space.

From the second line, the next $M$ lines each contain two distinct vertices $u$ and $v$ ($1 \leq u, v \leq N$) that form an edge of $G$, separated by a space.

It is guaranteed that no edge is given more than once.

Print the number of distinct simple cycles of length $4$ in $G$, modulo $10^9+7$.

Note that $10^9+7$ is a prime number.