n,m = map(int, input().split(' '))
a = [int(i) for i in input().split(' ')]

i = 1
t = []
while i <= n:
    t.append(i)
    i += 1

i = 0
while i < m:
    x = t[a[i]-1]
    t.remove(t[a[i]-1])
    t = [x] + t
    i += 1
print(t[0])