Ery is interested in graph theory, today he ask BrotherK a problem about it: Given you a undirected graph with $N$ vertexes and $M$ edges, you can select a vertex as your starting point, then you need to walk in the graph along edges. However, you can't pass a edge more than once, even opposite direction is forbidden. At the end, you should come back to the starting point. Assume you has passed $X$ edges, there are two questions:
Question 1: Can $X$ be a odd number ?
Question 2: Can $X$ be a even number ?
(note: you must walk, so $X$ can't be 0)