 // ???????? 
 // ??????
 // ???2010?12?10?
 // ?????????


int main()
{
	int n , i , j , k , a[100000] , b[100000] , c[100000] = { 0 } , g = 0 ; // g????????????                       
	cin >> n ;
	for ( i = 0 ; ; i++ )
	{
		cin >> a[i] >> b[i] ;
		if ( a[i] == 0 && b[i] == 0 )                                   // ??????
			break;
	}
	for ( j = 0 ; j <= i - 1 ; j++ )                                 // ?????????????????
	{
		c[b[j]] = c[b[j]] + 1 ;
	
	}
	for ( k = 0 ; k <= n - 1 ; k++ )                               // ???????????????
	{
		if ( c[k] == n - 1 )
		{
			if ( g == 0 )
			{
				cout << k ;
				g = 1 ;
			}
			else 
			{
				cout << " " << k ;
			}
		}
			
	}
	if ( g == 0 )
		cout << "NOT FOUND" << endl ;
	return 0 ;
}