import java.util.Scanner;


public class Main_yukicoder26 {

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

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

		System.out.println(n);

		sc.close();
    }
}