package yukicoder;

import java.util.Scanner;

public class No_026 {
public static void main(String[] args) {
	Scanner sc = new Scanner(System.in);
	int N = sc.nextInt();
	int M = sc.nextInt();
	int[] cup = new int[4];

	cup[N] = 1;
	for(int i = 0; i < M; i++){
		int[] shuf = new int[2];
		shuf[0] = sc.nextInt();
		shuf[1] = sc.nextInt();
		if(cup[shuf[0]] == 1){
			cup[shuf[0]] = 0;
			cup[shuf[1]] =1;
		}else if(cup[shuf[1]] == 1){
			cup[shuf[1]] = 0;
			cup[shuf[0]] = 1;
		}
	}
	for(int i = 1; i < 4; i ++){
		if(cup[i] == 1){
			System.out.println(i);
			break;
		}
	}
}
}