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

public class No26{
	public static void main(String[] args) {
		try{
			BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
			int cupNumAns = Integer.parseInt(br.readLine());
			int changeTimes = Integer.parseInt(br.readLine());
			System.out.println(changeCup(br, cupNumAns, changeTimes));
		}
		catch(IOException e){
			e.getStackTrace();
		}
		catch(NumberFormatException e){
			e.getStackTrace();
		}
	}
	
	public static int changeCup(BufferedReader br, int n, int m) throws IOException, NumberFormatException{
		for(int i=0; i < m; i++){
			String[] str = br.readLine().split(" ");
			int[] cupNum = new int[2];
			for(int j=0; j < 2; j++)
				cupNum[j] = Integer.parseInt(str[j]);
			if(n == cupNum[0]) n =cupNum[1];
			else if(n == cupNum[1]) n = cupNum[0];
		}
		return n;
	}
}