Connection Points 2

Input

The first line contains two natural numbers $n$ and $m$ — the number of vertices and the number of edges in the graph respectively ( $n \leq 620000$ n \leq 620\,000, $m \leq 6200000$ m \leq 6\,200\,000). Each of the next $m$ lines describes an edge with two natural numbers $b_{i}$ b_i, $e_{i}$ e_i ( $1 \leq b_{i}, e_{i} \leq n$ 1 \leq b_i, e_i \leq n) — the endpoints of the edge.

Output

On the first line, print the number of articulation points $b$ in the given graph. On the next line, print $b$ integers — the vertex numbers that are articulation points, in ascending order.

Examples

Example 1

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