import java.util.Scanner;

public class Main26 {
	public static void main(String[] args) {
		Main26 p = new Main26();
	}

	public Main26() {
		solve();
	}

	public void solve() {
		Scanner sc = new Scanner(System.in);
		int n =sc.nextInt();
		int m =sc.nextInt();
		
		int cur = n;
		for(int i=0;i<m;i++){
			int p = sc.nextInt();
			int q = sc.nextInt();
			if(p==cur)
				cur = q;
			else if(q==cur)
				cur = p;
		}
		
		System.out.println(cur);
		
	}

}