import java.util.Scanner;

class Main {
    public static void main(String[] args) throws Exception {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int m = in.nextInt();
        for(int i=0; i<m; i++) {
            int p = in.nextInt();
            int q = in.nextInt();
            if(p == n) {
                n = q;
            } else if(q == n) {
                n = p;
            }
        }

        System.out.println(n);
    }
}