In the mathematical discipline of graph theory, a matching in a graph is a set of edges without common vertices.
You are given an undirected graph with $n$ vertices, labeled by $1,2,...,n$. Initially the graph has no edges.
There are $2$ kinds of operations :
+ u v, add an edge $(u,v)$ into the graph, multiple edges between same pair of vertices are allowed.
- u v, remove an edge $(u,v)$, it is guaranteed that there are at least one such edge in the graph.
Your task is to compute the number of matchings with exactly $k$ edges after each operation for $k=1,2,3,...,\frac{n}{2}$. Note that multiple edges between same pair of vertices are considered different.