/*No.26 シャッフルゲーム*/
import java.io.*;
public class No26 {
	public static void main(String[] args) {
		try(BufferedReader input =new BufferedReader(new InputStreamReader(System.in))){
			String place = input.readLine();
			Short counter =Short.parseShort(input.readLine());
			String h_ChageCup[] = new String[2];
			String s_ChageCup;
			for(Short i=0;i<counter;i++){
				h_ChageCup=input.readLine().split(" ");
				s_ChageCup=h_ChageCup[0]+h_ChageCup[1];
				switch(s_ChageCup.indexOf(place)){
					case 0:
						place=h_ChageCup[1];
						break;
					case 1:
						place=h_ChageCup[0];
						break;						
					case -1:
						break;
				}
			}
			System.out.println(place);
		}catch(Exception e){
			e.printStackTrace();
		}		
	}
}