package m.shin;
import java.util.Scanner;
public class Con26 {

	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		int[] cup = new int[3];
		int N = s.nextInt() , M = s.nextInt();
		cup[N-1]++;

		for(int i = 0;i < M;i++){
			int p = s.nextInt() , q = s.nextInt();
			cup[q-1] += cup[p-1];
			cup[p-1] = 0;
		}
		s.close();

		for(int i = 0;i < 3;i++){
			if(cup[i] == 1){
				System.out.println(i+1);
			}
		}

	}

}