RedSocialN3

/*
    Timing:
        Reading: 2:12
        Coding: 37:59
*/
#include <bits/stdc++.h>
#define MAX 10000
using namespace std;
int n, d,e, maxl=0;
string a,b;
vector< string > p, res;
vector<string>::iterator it;
vector< vector< int > > lista(MAX);
vector< bool > v;
pair<int,int> temp;

void dfs(int index, vector<bool> vis, int l){
    if(!vis[index]){
        vis[index]=true;

        if(l > maxl){
            res.clear();
            maxl = l;
            if(find(res.begin(), res.end(), p[index]) == res.end())
                res.push_back(p[index]);
        } else if(l == maxl){
            if(find(res.begin(), res.end(), p[index]) == res.end())
                res.push_back(p[index]);
        }

        for(int i=0;i<lista[index].size();i++){
            dfs(lista[index][i], vis, l+1);
        }
    }
}

void push_safe(string s){
    it = find(p.begin(), p.end(), s);
    if(it == p.end()){
        v.push_back(false);
        p.push_back(s);
    }
}

int main(){
    ifstream fin("in.txt");
    fin >> n;

    while(fin >> a >> b){
        push_safe(a);
        push_safe(b);

        it = find(p.begin(), p.end(), a);
        d = distance(p.begin(), it);
        it = find(p.begin(), p.end(), b);
        e = distance(p.begin(), it);

        lista[d].push_back(e);
        lista[e].push_back(d);
    }

    for(int i=0;i<p.size();i++)
        dfs(i, v, 0);

    cout << res.size() << ' ' << maxl << endl;

    sort(res.begin(), res.end());

    for(int i=0;i<res.size();i++)
        cout << res[i] << endl;
}