# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")
import copy

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	N, M = getlist()
	A = getlist()
	card = [(i + 1) for i in range(N)]
	for i in range(M):
		itr = A[i]
		card = [card[itr - 1]] + copy.copy(card[:itr - 1]) + copy.copy(card[itr:])
		# print(card)

	print(card[0])

if __name__ == '__main__':
	main()