import java.util.*;

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