import java io File import java io FileNotFoundExceptio import java ut

import java.io.File;
import java.io.FileNotFoundException;
import java.util.*;

public class MyClass  {
    public static void main(String[] args) throws FileNotFoundException {

        Scanner scanner = new Scanner(new File("example.txt"));
        String line = scanner.nextLine().trim();

        int n = line.charAt(0) - '0';
        int [][] arr = new int[n + 1][n + 1]; //матрица инциндентности

        line = scanner.nextLine().trim();

        int i = 0;
        while (i < line.length() - 2) {
            int a1 = line.charAt(i) - '0';
            System.out.println(a1);

            int a2 = line.charAt(i + 2) - '0';
            System.out.println(a2);

            arr[a1][a2]++;
            i += 4;
        }

        line = scanner.nextLine().trim();
        int source = line.charAt(0) - '0';

        int topological_sort[]  = null;


        System.out.print("Result: ");
        TopologicalSort topologicalSort = new TopologicalSort();
        topological_sort = topologicalSort.topological(arr, source);
        for (i = topological_sort.length - 1; i > 0; i-- ) {
            if (topological_sort[i] != 0)
                System.out.print(topological_sort[i]+" ");
        }
    }
}