import java.util.Scanner;
	

public class Main{
	
	
	public static void main(String args[])throws Exception{
		
		Scanner sc = new Scanner(System.in);
		int N = sc.nextInt();
		int M = sc.nextInt();
		for(int i=0;i<M;i++){
			int p = sc.nextInt();
			int q = sc.nextInt();
			if(N==p){
				N=q;
			}else if(N==q){
				N=p;
			}
		}
		System.out.println(N);
	}
	
}