#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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