import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) {
	      BufferedReader stdReader =new BufferedReader(new InputStreamReader(System.in));
	      try {
		      int ans = Integer.parseInt(stdReader.readLine());
		      int M = Integer.parseInt(stdReader.readLine());
		      
		      for(int i=0;i<M;i++){
		    	  String temps[] = stdReader.readLine().split(" ");
		    	  if(ans == Integer.parseInt(temps[0])){
		    		  ans = Integer.parseInt(temps[1]);
		    	  }else if(ans == Integer.parseInt(temps[1])){
		    		  ans = Integer.parseInt(temps[0]);
		    	  }
		      }
		      System.out.println(ans);
	    	  } catch (IOException e) {
			e.printStackTrace();
	      }
	}	
}