Cirno was recommended a game, and she decided to play it with Daiyousei today. Initially, there is a graph with 2 × n vertexes and m edges. At every turn, both Cirno and Daiyousei have to choose one distinct vertex. The degree of two choson vertexes must be the same. Then, Cirno and Daiyousei will remove them from the graph. Now Cirno wanted to know is there any way to remove all the vertex from the given graph. If it exist, please give an example.
Cirno was recommended a game, and she decided to play it with Daiyousei today. Initially, there is a graph with 2 × n vertexes and m edges. At every turn, both Cirno and Daiyousei have to choose one distinct vertex. The degree of two choson vertexes must be the same. Then, Cirno and Daiyousei will remove them from the graph. Now Cirno wanted to know is there any way to remove all the vertex from the given graph. If it exist, please give an example.
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