"Bzoj 1006" [HNOI2008] The Magical kingdom

Description

K Country is a country of keen triangles, even people's contacts only like the triangle principle. They think triangular relationship: AB Mutual understanding, BC Mutual Understanding, CA mutual understanding, is concise and efficient. In order to consolidate triangular relations, the K-State prohibits the existence of four-sided relations, five-sided relations and so on ... There is only n pairs of cognitive relationships between an: (A1A2) (A2A3) ... (AnA1), and there is no other understanding. For example, four-sided relationship refers to ABCD four people ab,bc,cd,da mutual understanding, and ac,bd do not know. When the national competition, in order to prevent the harm, the provision of any pair of mutual understanding of the person must not be in a team, the king knows, at least how many detachment.

Input

The first row of two integers n,m. 1<=n<=10000,1<=m<=1000000. Indicates that there are N individuals, M to the cognitive relationship. Next, enter a pair of friends on each line of M line

Output

Output an integer, at least how many teams can be divided

Sample Input4 5
1 2
1 4
2 4
2 3
3 4Sample Output3HINT

One scenario (1,3) (2) (4)

Most trend algorithm ... What the hell is that? string coloring ... I admit that I still do not understand. Basically it means to mark a picture from the beginning of the big, at the same time for points connected to the mark Point du++, the next mark is unmarked Point du the largest point, so as to form a queue in order to dye the queue, each Dianran the smallest color is OK, I do not know why this is right ...

1#include <cstdio>2 intn,m,cnt,ans,u,v,x,t;3 inthead[10005],du[10005],q[10005],col[10005],hash[10005];4 BOOLvis[10005];5 structdata{intTo,next;} e[2000005];6 voidInsintUintv)7{e[++cnt].to=v;e[cnt].next=head[u];head[u]=CNT;}8 intMain () {9scanf"%d%d",&n,&m);Ten      for(intI=1; i<=m;i++){ Onescanf"%d%d",&u,&v); A ins (u,v); ins (v,u); -     } -du[0]=-1; the      for(inti=n;i>=1; i--){ -         intx=0; -          for(intj=1; j<=n;j++) -             if(!vis[j]&&du[j]>du[x]) x=J; +vis[x]=1; q[i]=x; -          for(intj=head[x];j;j=E[j].next) { +             intv=e[j].to; Adu[v]++; at         } -     } -      for(intI=n;i>0; i--){ -          for(intJ=head[q[i]];j;j=e[j].next) hash[col[e[j].to]]=i; -         intj=1; -          while(hash[j]==i) J + +; incol[q[i]]=J; -         if(J>ans) ans=J; to     } +printf"%d", ans); -}

"Bzoj 1006" [HNOI2008] The Magical kingdom