백준 1547 java

import java.util.Scanner;
import java.util.Vector;

public class bj1547 {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);

        int M;
        Vector<Vector<Integer>> cup = new Vector<>();
        int X, Y;
        int i, currentCup = 1;

        M = scanner.nextInt();
        for(i = 0; i < M; i++)
        {
            Vector<Integer> temp = new Vector<>();
            X = scanner.nextInt();
            Y = scanner.nextInt();
            temp.add(X);
            temp.add(Y);
            cup.add(temp);
        }
        for(i = 0; i < cup.size(); i++)
        {
            X = cup.get(i).get(0);
            Y = cup.get(i).get(1);
            if(X == currentCup)
            {
                currentCup = Y;
            }
            else if(Y == currentCup)
            {
                currentCup = X;
            }
            else
            {
                ;
            }
        }
        System.out.println(currentCup);

        scanner.close();
    }
}