#include<iostream>

#include<cstdio>

#include<cstring>

#include<string>

#include<map>

using namespace std;

int n,m;

map<string,int> ma;

map<int,string> mb;

int maps[][],vis[];

void dfs(int u)

{

    vis[u] = ;

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

    {

        if(!vis[i] && maps[u][i] && maps[i][u])

        {

            cout<<", "<<mb[i];

            dfs(i);

        }

    }

    return ;

}

int main()

{

    string a,b;

    int tot,u,v,ca =  ;

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

    {

        if(n+m == ) break;

        ma.clear();

        mb.clear();

        memset(maps,,sizeof(maps));

        tot = ;

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

        {

            cin>>a>>b;

            if(!ma[a]) ma[a] = tot++;

            if(!ma[b]) ma[b] = tot++;

            u = ma[a]; v = ma[b];

            mb[u] = a; mb[v] = b;

            maps[u][v] = ;

        }

        for(int k = ;k <= n;k++)

        {

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

            {

                for(int j = ;j <= n;j++)

                {

                    maps[i][j] = maps[i][j] || (maps[i][k]&&maps[k][j]);

                }

            }

        }

        memset(vis,,sizeof(vis));

        if(!ca) puts("");

        printf("Calling circles for data set %d:\n",++ca);

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

        {

            if(!vis[i])

            {

                cout<<mb[i];

                dfs(i);

                cout<<endl;

            }

        }

    }

}