import java.util.*;
import java.lang.*;
import java.io.*;

class Main {
    public static void main(String[] args) throws IOException{
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        StringTokenizer st = new StringTokenizer(br.readLine());
        
        int N = Integer.parseInt(st.nextToken());
        int X = Integer.parseInt(st.nextToken());

        ArrayList<ArrayList<Integer>> graph = new ArrayList<>();
        for (int i=0; i<N; i++) {
            graph.add(new ArrayList<>());
        }
        int[] parent = new int[N];
        for (int i=0; i<N-1; i++) {
            st = new StringTokenizer(br.readLine());
            int a = Integer.parseInt(st.nextToken());
            int b = Integer.parseInt(st.nextToken());
            graph.get(a).add(b);
            parent[b] = a;
        }

        int[] graph_arr = new int[N];
        graph[0] = X;
        for ()

    }
}