L = []
M = list(map(int, input().split()))
N = list(map(int, input().split()))
for i in range(M[0]):
    L.append(int(i) + 1)
for i in range(M[1]):
    a = N[i]
    b = L[a - 1]
    L.pop(a - 1)
    L.insert(0, b)
print(L[0])