#include<stdio.h>
#include<memory.h>
int map[200][200],mark[200],m,n;
void make(int v){
    int i;
    for (i=0;i<n;i++)
        if (mark[i]==0 && map[v][i]>0) {
            mark[i]=v+1;
            map[v][i]=-map[v][i];
            map[i][v]=-map[i][v];
            make(i);
        }
}
void main(){
    int i,j,aa,bb,la,lb,a[200],b[200],count,k;
    scanf("%d%d",&n,&m);
    memset(map,0,sizeof map);
    for (i=0;i<m;i++) {
        scanf("%d%d",&aa,&bb);
        map[aa-1][bb-1]=map[bb-1][aa-1]=1;
    }
    memset(mark,0,sizeof mark);
    i=0;
    do{
        while (i<n && mark[i]) i++;
        if (i==n) break;
        mark[i]=32767;
        make(i);
    }while (1);
    count=0;
    for (i=0;i<n;i++)
        for (j=i+1;j<n;j++) if (map[i][j]>0) count++;
    printf("%d\n",count);
    for (i=0;i<n;i++)
        for (j=i+1;j<n;j++)
        if (map[i][j]>0) {
            la=0;
            aa=i;
            do{
                a[la++]=aa;
                if (mark[aa]==32767) break;
                aa=mark[aa]-1;
            }while (1);
            lb=0;
            bb=j;
            do{
                b[lb++]=bb;
                if (mark[bb]==32767) break;
                bb=mark[bb]-1;
            }while(1);

            while (a[la-1]==b[lb-1]) {la--;lb--;}
            printf("%d ",la+lb+1);
            for (k=0;k<la+1;k++) printf("%d ",a[k]+1);
            for (k=lb-1;k>=0;k--) printf("%d ",b[k]
+1);
            printf("\n");
        }
}

> #include<stdio.h>
> #include<memory.h>
> int map[200][200],mark[200],m,n;
> void make(int v){
>     int i;
>     for (i=0;i<n;i++)
>         if (mark[i]==0 && map[v][i]>0) {
>             mark[i]=v+1;
>             map[v][i]=-map[v][i];
>             map[i][v]=-map[i][v];
>             make(i);
>         }
> }
> void main(){
>     int i,j,aa,bb,la,lb,a[200],b[200],count,k;
>     scanf("%d%d",&n,&m);
>     memset(map,0,sizeof map);
>     for (i=0;i<m;i++) {
>         scanf("%d%d",&aa,&bb);
>         map[aa-1][bb-1]=map[bb-1][aa-1]=1;
>     }
>     memset(mark,0,sizeof mark);
>     i=0;
>     do{
>         while (i<n && mark[i]) i++;
>         if (i==n) break;
>         mark[i]=32767;
>         make(i);
>     }while (1);
>     count=0;
>     for (i=0;i<n;i++)
>         for (j=i+1;j<n;j++) if (map[i][j]>0) count++;
>     printf("%d\n",count);
>     for (i=0;i<n;i++)
>         for (j=i+1;j<n;j++)
>         if (map[i][j]>0) {
>             la=0;
>             aa=i;
>             do{
>                 a[la++]=aa;
>                 if (mark[aa]==32767) break;
>                 aa=mark[aa]-1;
>             }while (1);
>             lb=0;
>             bb=j;
>             do{
>                 b[lb++]=bb;
>                 if (mark[bb]==32767) break;
>                 bb=mark[bb]-1;
>             }while(1);
>
>             while (a[la-1]==b[lb-1]) {la--;lb--;}
>             printf("%d ",la+lb+1);
>             for (k=0;k<la+1;k++) printf("%d ",a[k]+1);
>             for (k=lb-1;k>=0;k--) printf("%d ",b[k]
> +1);
>             printf("\n");
>         }
> }