import java.util.*;
 

public class Main {
	
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		int m=sc.nextInt();
		for(int i=0;i<m;i++){
			int a = sc.nextInt();
			int b = sc.nextInt();
			if(a==n) n=b;
			else if(b==n) n=a;
		}
		System.out.println(n);
	}
}