Bridges

Input

The first line contains two integers $n$ and m~(n \le 2 \cdot 10^4, m \le 2 \cdot 10^5) — the number of vertices and the number of edges in the graph.

Each of the next $m$ lines describes an edge and contains two integers b_i and e_i~(1 \le b_i, e_i \le n) — the endpoints of the $i$-th edge.

Output

In the first line, print an integer $b$ — the number of bridges in the graph.

In the second line, print $b$ integers — the numbers of the edges that are bridges, in increasing order. The edges are numbered starting from $1$ in the order in which they are given in the input.

Examples