import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m = sc.nextInt();
		int point = n;
		for(int i = 0 ; i < m ; i++) {
			int a = sc.nextInt();
			int b = sc.nextInt();
			if(point == a) point = b;
			else if(point == b) point = a;
		}
		System.out.println(point);
 	}
}