package me.yukicoder.lv1;

import java.util.Scanner;

public class No0026 {
	public static void main(String[] args) {
		try (Scanner sc = new Scanner(System.in);) {
			int N = sc.nextInt();
			int M = sc.nextInt();
			int mark = N;

			for (int i = 0; i < M; i++) {
				int p = sc.nextInt();
				int q = sc.nextInt();
				
				if (mark == p) {
					mark = q;
				}
				else if (mark == q) {
					mark = p;
				}
			}

			System.out.println(mark);
		}
	}
}