P5746 [CF813F] Bipartite Checking
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题目描述

You are given an undirected graph consisting of n vertices. Initially there are no edges in the graph. Also you are given q queries, each query either adds one undirected edge to the graph or removes it. After each query you have to check if the resulting graph is bipartite (that is, you can paint all vertices of the graph into two colors so that there is no edge connecting two vertices of the same color).

Input

The first line contains two integers n and q (2 ≤ n, q ≤ 100000).

Then q lines follow. ith line contains two numbers xi and yi (1 ≤ xi < yi ≤ n). These numbers describe ith query: if there is an edge between vertices xi and yi, then remove it, otherwise add it.

Output

Print q lines. ith line must contain YES if the graph is bipartite after ith query, and NO otherwise.

输入格式

见题面 Input 部分

输出格式

见题面 Output 部分

样例输入
3 5 2 3 1 3 1 2 1 2 1 2
样例输出
YES YES NO YES NO