import java.util.Scanner;
class N026{
	public static void main(String args[]){
		Scanner s = new Scanner(System.in);
		int n = s.nextInt();
		int m = s.nextInt();
		for(int i = 0; i < m; i++){
			int p = s.nextInt();
			int q = s.nextInt();
			if(p == n){
				n = q;
			}else if(q == n){
				n = p;
			}
		}
		System.out.println(n);
	}
}