#include<bits/stdc++.h>

using namespace std;

const int maxn = ;

map<string,int> mp;

map<string,int>::iterator it;

vector<string> names;

bool d[maxn][maxn];

int ID(const string& s)

{

    if((it = mp.find(s))!=mp.end()) return it->second;

    mp.insert(make_pair(s,names.size()));

    names.push_back(s);

    return names.size()-;

}

bool vis[maxn];

int n,m;

void dfs(int u)

{

    vis[u] = true;

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

        if(!vis[i] && d[u][i] && d[i][u]){

            printf(", %s",names[i].c_str());

            dfs(i);

        }

    }

}

int main()

{

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

    char s1[],s2[];

    int kas = ;

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

        if(kas) putchar('\n');

        memset(d,,sizeof(d));

        names.clear(); mp.clear();

        while(m--) {

            scanf("%s%s",s1,s2);

            d[ID(s1)][ID(s2)] = true;

        }

        for(int i = ; i < n; i++) d[i][i] = true;

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

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

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

            d[i][j] |= d[i][k]&&d[k][j];

        }

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

        fill(vis,vis+n,);

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

            if(!vis[i]){

                printf("%s",names[i].c_str());

                dfs(i);

                putchar('\n');

            }

        }

    }

    return ;

}