Problem
A directed graph is semi-connected if for all pairs of vertices $i,j$ there is either a path from
$i$ to $j$ or a path from $j$ to $i$.
Given: A positive integer $k \le 20$ and $k$ simple directed graphs with at most $10^3$ vertices each in the edge list format.
Return: For each graph, output "1" if the graph is semi-connected and "-1" otherwise.
Sample Dataset
2
3 2
3 2
2 1
3 2
3 2
1 2
Sample Output
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