input_params = list(map(int,input().split()))
n = input_params[0]
m = input_params[1]
a = list(map(int,input().split()))
card = list(range(1, n+1))

for i in range(len(a)):
    get = card[a[i]-1]
    card.pop(a[i]-1)
    card.insert(0, get)

print(card[0])