n, m = map(int,input().split())
shuf = list(map(int,input().split()))
x = []
for i in range(n) :
    x.append(i+1)
for i in range(m) :
    card = x[shuf[i]-1]
    del x[shuf[i]-1]
    x.insert(0,card)
print(x[0])