//用弗洛伊德算法思想

#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <map>
using namespace std;

vector<int> label;
vector<int> dataIndex;



void AddDependency(unsigned int Moduled, unsigned int DeModuled)
{
    for(int i = 0; i < label.size(); ++i)
    {
        if(Moduled == label[i])
        {
            dataIndex.push_back(Moduled);
            break;
        }
    }
    for(int j = 0; j < label.size(); ++j)
    {
        if(DeModuled == label[j])
        {
            dataIndex.push_back(DeModuled);
            break;
        }
    }
}


int main()
{
    vector<string> input;
    vector<int> result;
    string temp;
    while(getline(cin, temp))
    {
        input.push_back(temp);
    }
    int len = input.size();

    for(int i = 0; i < len; i++)
    {
        temp = input[i];
        int k = 3;
        int num = 0;
        while(temp[k] != ',')
        {
            if(temp[k] >= '0' && temp[k] <= '9')
            {
                num = num * 16 + temp[k] - '0';
                k++;
            }
            else
            {
                num = num * 16 + temp[k] - 'a';
                k++;
            }

        }
        result.push_back(num);
        num = 0;
        k = k + 4;
        while(temp[k] != '}')
        {
            if(temp[k] >= '0' && temp[k] <= '9')
            {
                num = num * 16 + temp[k] - '0';
                k++;
            }
            else
            {
                num = num * 16 + temp[k] - 'a';
                k++;
            }
        }
        result.push_back(num);
        num = 0;

    }
/*
    vector<int> time;
    vector<int> duitime;
    map<int, int> Hash;
    for(int i = 0; i < result.size()-1; i += 2)
    {
        ++Hash[result[i+1]];
    }
    map<int, int>::iterator mapi;

    for(mapi = Hash.begin(); mapi != Hash.end(); mapi++)
    {
        int a = mapi->first;
        int b = mapi->second;
        duitime.push_back(a);
        time.push_back(b);
    }

*/




    vector<int> result_temp(result);
    sort(result_temp.begin(), result_temp.end());


    label.push_back(result_temp[0]);
    for(int i = 1; i < result_temp.size(); i++)
    {
        if(result_temp[i] != result_temp[i-1])
            label.push_back(result_temp[i]);
    }

/*
    for(int i = 0; i < label.size(); i++)
        cout << label[i] << endl << endl;
*/
    for(int i = 0; i < result.size()-1; i += 2)
    {
        AddDependency(result[i], result[i+1]);
    }
/*
    for(int i = 0; i < dataIndex.size(); i++)
        cout << dataIndex[i] << endl;
*/
    int **arr = new int*[label.size()];
    for(int i = 0; i < label.size(); i++)
        arr[i] = new int[label.size()];


    //初始化数组为全0；

    for(int i = 0; i < label.size(); i++)
        for(int j = 0; j < label.size(); j++)
            arr[i][j] = 0;




    for(int i = 0; i < result.size()-1; i += 2)
    {
        arr[dataIndex[i]-1][dataIndex[i+1]-1] = 1;
    }

/*
    for(int i = 0; i < label.size(); i++)
    {
        for(int j = 0; j < label.size(); j++)
            cout << arr[i][j] << ' ';
        cout << endl;
    }


    cout << endl;

*/

    for(int i = 0; i < label.size(); i++)
    {
        for(int j = 0; j < label.size(); j++)
        {
            for(int k = 0; k < label.size(); k++)
            {
                if(arr[j][i] == 1 && arr[i][k] == 1)
                {
                    arr[j][k] = 1;
                }
            }
        }
    }


/*
    for(int i = 0; i < label.size(); i++)
    {
        for(int j = 0; j < label.size(); j++)
            cout << arr[i][j] << ' ';
        cout << endl;
    }


    cout << endl;

*/


//输出的格式没有调
    for(int i = 0; i < label.size(); ++i)
    {
        if(arr[i][i] == 1)
            cout << label[i] << endl;
    }



//最后需要释放内存


    return 0;
}