import java.util.*;
public class card{
	public static void main(String... args){
		Scanner scan = new Scanner(System.in);
		int n = scan.nextInt();
		int m = scan.nextInt();
		int[] number = new int[n];
		for(int i = 0; i < n; i++){
			number[i] = i+1;
		}
		System.out.println(cardShuffle(number,m,scan));
	}
	public static int cardShuffle(int[] number,int m,Scanner scan){
		for(int i = 0; i < m; i++){
			int shuffle_number = scan.nextInt();
			int now = number[shuffle_number-1];
			for(int j = shuffle_number-1; 0 < j; j--){
				number[j] = number[j-1];
			}
			number[0] = now;
		}
		return number[0];
	}
}