#include<iostream>
 
using namespace std;
 
int main()
{
    int t;
    cin>>t;
    int lo , lw , zr , a , b , c;
    c = 1;
    cin>>lo>>lw>>zr;
    int * tab = new int[lo];
    tab [0] = zr;
    while (t--)
    {
        for ( int i = 0 ; i < lw ; i++)
        {
            cin >> a >> b;
            for (int j = 0 ; j < lo ; j++)
            {
                if ( tab[j] == a )
                {
                    tab[c] = b;
                    c++;
                }
 
            }
        }
            for (int j = 0 ; j < lo ; j++)
            {
            if (tab [ j ] != 0)
cout<<tab[j]<<" ";
                }
    }
 
}
 

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