package yukicoder;

import java.util.Scanner;

public class No_26v2 {
public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int[] cup = new int[3];
	int N = sc.nextInt();
	int M = sc.nextInt();
	cup[N - 1] = 1;
	for(int i = 0; i < M; i++){
		int sf1 = sc.nextInt() - 1;
		int sf2 = sc.nextInt() - 1;
		if(cup[sf1] == 0 && cup[sf2] == 0){
			continue;
		}else if(cup[sf1] == 1){
			cup[sf1] = 0;
			cup[sf2] = 1;
		}else if(cup[sf2] == 1){
			cup[sf1] = 1;
			cup[sf2] = 0;
		}
	}
	sc.close();
	for(int i = 0; i < 3; i++){
		if(cup[i] == 1){
			System.out.println(i + 1);
			break;
		}
	}
}
}