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();
        int[] p = new int[m];
        int[] q = new int[m];

        for(int i=1; i<=m; i++) {
            p[i] = in.nextInt();
            q[i] = in.nextInt();
        }

        int temp = n;
        for(int i=1; i<=m; i++) {
            if(p[i] != temp && q[i] != temp) continue;
            if(p[i] == temp) {
                temp = q[i];
            }
            if(q[i] == temp) {
                temp = p[i];
            }
        }

        System.out.println(temp);
    }
}