import java.util.Scanner;


public class Main {
	public static void main(String[] a) {
		Scanner s=new Scanner(System.in);
		int[] C=new int[4];C[s.nextInt()]=1;
		s.nextInt();
		while(s.hasNext()){
			int i=s.nextInt(),j=s.nextInt(),t=C[i];
			C[i]=C[j];C[j]=t;
		}
		System.out.println(C[1]>0?1:C[2]>0?2:3);
	}
}