write a go solution for Description:
You are given a directed graph G which can contain loops (edges from a vertex to itself). Multi-edges are absent in G which means that for all ordered pairs (u,v) exists at most one edge from u to v. Vertices are numbered from 1 to n.

A path from u to v is a sequence of edges such that:

- vertex u is the start of the first edge in the path;
- vertex v is the end of the last edge in the path;
- for all pairs of adjacent edges next edge starts at the vertex that the previous edge ends on.

We will assume that the empty sequence of edges is a path from u to u.

For each vertex v output one of four values:

- 0, if there are no paths from 1 to v;
- 1, if there is only one path from 1 to v;
- 2, if there is more than one path from 1 to v and the number of paths is finite;
- -1, if the number of paths from 1 to v is infinite.

Let's look at the example shown in the figure.

Then:

- the answer for vertex 1 is 1: there is only one path from 1 to 1 (path with length 0);
- the answer for vertex 2 is 0: there are no paths from 1 to 2;
- the answer for vertex 3 is 1: there is only one path from 1 to 3 (it is the edge (1,3));
- the answer for vertex 4 is 2: there are more than one paths from 1 to 4 and the number of paths are finite (two paths: [(1,3),(3,4)] and [(1,4)]);
- the answer for vertex 5 is -1: the number of paths from 1 to 5 is infinite (the loop can be used in a path many times);
- the answer for vertex 6 is -1: the number of paths from 1 to 6 is infinite (the loop can be used in a path many times).

Input Format:
The first contains an integer t (1<=t<=10^4) — the number of test cases in the input. Then t test cases follow. Before each test case, there is an empty line.

The first line of the test case contains two integers n and m (1<=n<=4*10^5,0<=m<=4*10^5) — numbers of vertices and edges in graph respectively. The next m lines contain edges descriptions. Each line contains two integers a_i, b_i (1<=a_i,b_i<=n) — the start and the end of the i-th edge. The vertices of the graph are numbered from 1 to n. The given graph can contain loops (it is possible that a_i=b_i), but cannot contain multi-edges (it is not possible that a_i=a_j and b_i=b_j for inej).

The sum of n over all test cases does not exceed 4*10^5. Similarly, the sum of m over all test cases does not exceed 4*10^5.

Output Format:
Output t lines. The i-th line should contain an answer for the i-th test case: a sequence of n integers from -1 to 2.

Note:
None. Output only the code with no comments, explanation, or additional text.