Problem Statement
You are given a simple connected undirected graph with $N$ vertices and $M$ edges. (A graph is said to be simple if it has no multi-edges and no self-loops.)
For $i = 1, 2, \ldots, M$, the $i$-th edge connects Vertex $u_i$ and Vertex $v_i$.
A sequence $(A_1, A_2, \ldots, A_k)$ is said to be a path of length $k$ if both of the following two conditions are satisfied:
- For all
$i = 1, 2, \dots, k$, it holds that$1 \leq A_i \leq N$. - For all
$i = 1, 2, \ldots, k-1$, Vertex$A_i$and Vertex$A_{i+1}$are directly connected with an edge.
An empty sequence is regarded as a path of length $0$.
You are given a sting $S = s_1s_2\ldots s_N$ of length $N$ consisting of $0$ and $1$. A path $A = (A_1, A_2, \ldots, A_k)$ is said to be a good path with respect to $S$ if the following conditions are satisfied:
- For all
$i = 1, 2, \ldots, N$, it holds that: - if
$s_i = 0$, then$A$has even number of$i$'s.- if
$s_i = 1$, then$A$has odd number of$i$'s.
- if
Under the Constraints of this problem, it can be proved that there is at least one good path with respect to $S$ of length at most $4N$. Print a good path with respect to $S$ of length at most $4N$.
Constraints
$2 \leq N \leq 10^5$$N-1 \leq M \leq \min\lbrace 2 \times 10^5, \frac{N(N-1)}{2}\rbrace$$1 \leq u_i, v_i \leq N$- The given graph is simple and connected.
$N, M, u_i$, and$v_i$are integers.$S$is a string of length$N$consisting of$0$and$1$.
Input
Input is given from Standard Input in the following format:
N M
u_1 v_1
u_2 v_2
\vdots
u_M v_M
S
Output
Print a good path with respect to $S$ of length at most $4N$ in the following format. Specifically, the first line should contain the length $K$ of the path, and the second line should contain the elements of the path, with spaces in between.
K
A_1 A_2 \ldots A_K
样例
6 6
6 3
2 5
4 2
1 3
6 5
3 2
110001
9
2 5 6 5 6 3 1 3 6
3 3
3 1
3 2
1 2
000
0
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