SP16909 EC_P - Critical Edges

This time I will not bore you with a long and boring sentence. Give a connected graph, you must find all the edges that are critical, in other words you must find the edges which when removed divide the graph.

The first line contains a NC (1

For each test case print the list of ways to protect the following format: Caso # ... Where **n** is the case number (starting from 1), **t** is the total of critical edges, list elements **x $ _{i} $ y $ _{i} $** indicates, for each line, there is a critical edge between the node x $ _{i} $ and node y $ _{i} $ (1 x $ _{i} $ and then by **y $ _{i} $** . Also **x $ _{i} $ < y $ _{i} $** must hold. If there isn't any critical edge print: "Sin bloqueos" (quotes for clarity).