#include <iostream>

 #include <cstdio>

 #include <cstring>

 #include <cstdlib>

 #include <cmath>

 #include <ctime>

 #include <algorithm>

 #include <queue>

 using namespace std;

 template<const int _n>

 struct    Edge

 {

     struct Edge_base { int    to,next,w; }e[_n];

     int    cnt,p[_n];

     Edge() { clear(); }

     int    start(const int x) { return p[x]; }

     void    insert(const int x,const int y,const int z)

     { e[++cnt].to=y; e[cnt].next=p[x]; e[cnt].w=z; p[x]=cnt; return ; }

     Edge_base&    operator[](const int x) { return e[x]; }

     void    clear() { cnt=,memset(p,,sizeof(p)); }

 };

 int    n,m,SSS,TTT,Ans;

 int    level[],cur[],Out[],to[],from[];

 bool    visited[];

 Edge<>    e;

 bool    Bfs(const int S)

 {

     int    i,t;

     queue<int>    Q;

     memset(level,,sizeof(level));

     level[S]=;

     Q.push(S);

     while(!Q.empty())

     {

         t=Q.front();Q.pop();

         for(i=e.start(t);i;i=e[i].next)

         {

             if(!level[e[i].to] && e[i].w)

             {

                 level[e[i].to]=level[t]+;

                 Q.push(e[i].to);

             }

         }

     }

     return level[TTT];

 }

 int    Dfs(const int S,const int bk)

 {

     if(S==TTT)return bk;

     int    rest=bk;

     for(int &i=cur[S];i;i=e[i].next)

     {

         if(level[e[i].to]==level[S]+ && e[i].w)

         {

             int    flow=Dfs(e[i].to,min(e[i].w,rest));

             e[i].w-=flow;

             e[i^].w+=flow;

             if((rest-=flow)<=)break;

         }

     }

     if(bk==rest)level[S]=;

     return bk-rest;

 }

 int    Dinic()

 {

     int    flow=;

     while(Bfs(SSS))

     {

         memcpy(cur,e.p,sizeof(int)*(n+n+));

         flow+=Dfs(SSS,0x3f3f3f3f);

     }

     return flow;

 }

 int main()

 {

     freopen("path3.in","r",stdin);

     freopen("path3.out","w",stdout);

     int    i,j,x,y;

     scanf("%d%d",&n,&m);

     for(i=;i<=m;++i)

     {

         scanf("%d%d",&x,&y);

         e.insert(x,y+n,);

         e.insert(y+n,x,);

         Out[x]++;

     }

     SSS=n+n+,TTT=n+n+;

     for(i=;i<=n;++i)

     {

         e.insert(SSS,i,);

         e.insert(i,SSS,);

         e.insert(i+n,TTT,);

         e.insert(TTT,i+n,);

     }

     Dinic();

     for(i=e.start(SSS);i;i=e[i].next)

     {

         if(e[i].w)continue;

         for(j=e.start(e[i].to);j;j=e[j].next)

         {

             if(e[j].to!=SSS && !e[j].w)

             {

                 to[e[i].to]=e[j].to-n;

                 from[e[j].to-n]=e[i].to;

                 break;

             }

         }

     }

     for(i=;i<=n;++i)

     {

         if(!from[i])

         {

             int t=i;

             while(t)

             {

                 printf("%d ",t);

                 t=to[t];

             }

             printf("\n");

             Ans++;

         }

     }

     printf("%d\n",Ans);

     return ;

 }