#include<iostream>

#include<cstdio>

#include<algorithm>

#include<cstring>

#include<stack>

#include<vector>

using namespace std;

#define maxn 7500

#define inf 0x3f3f3f3f

int n,m;

int g[maxn][maxn];

int clock;

int low[maxn],pre[maxn];

stack<int>s;

int bc;

vector<int>bcc[maxn];

int dfs(int u,int fa){

     low[u]=pre[u]=++clock;

     s.push(u);

     for(int v=1;v<=n;v++){

        if(!g[u][v])continue;

        if(!pre[v]){

            int lowv=dfs(v,u);

            low[u]=min(low[u],lowv);

            if(lowv>=pre[u]){

                bc++;

                bcc[bc].clear();

                int tmp=-1;

                while(!s.empty()){

                    tmp=s.top();

                    s.pop();

                    bcc[bc].push_back(tmp);

                    if(tmp==u)break;

                }

                if(tmp!=-1)s.push(tmp);  //割顶要加回去，随意割顶至少是两个不同双联通分量的公共点

            }

        }

       else if(pre[v]<pre[u]&&fa!=v){

            low[u]=min(low[u],pre[v]);

        }

     }

     return low[u];

}

void inital(){

    clock=0;

    bc=0;

    memset(pre,0,sizeof pre);

    memset(low,inf,sizeof low);

    while(!s.empty()){

        s.pop();

    }

}

int main()

{

    int u,v;

    freopen("in.txt","r",stdin);

    while(~scanf("%d%d",&n,&m)){

        inital();

        for(int i=0;i<m;i++){

            scanf("%d%d",&u,&v);

            g[u][v]=g[v][u]=1;

        }

        for(int i=1;i<=n;i++){

            if(!pre[i])dfs(i,-1);

        }

         for(int i=1;i<=n;i++){

            printf("%d %d\n",pre[i],low[i]);

        }

        printf("以下是点联通分量%d:\n",bc);

        for(int i=1;i<=bc;i++){

            printf("%d:",i);

            for(int j=0;j<bcc[i].size();j++){

                printf("%d ",bcc[i][j]);

            }

            printf("\n");

        }

    }

}