백준 1547 Java 자바

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.util.StringTokenizer;
 
public class Q1547 {
 
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        int m = Integer.parseInt(br.readLine());
        
        int cup[] = {0, 1, 0, 0};
                
        for(int i = 0; i < m; i++) {
            StringTokenizer st = new StringTokenizer(br.readLine());
            int x = Integer.parseInt(st.nextToken());
            int y = Integer.parseInt(st.nextToken());
            int temp = cup[x];
            cup[x] = cup[y];
            cup[y] = temp;
        }
        
        for(int i = 1; i < 4; i++) {
            if(cup[i] == 1) {
                System.out.println(i);
                return;
            }
        }
    }
 
}