N,M = [int(i) for i in input().split()]
N0 = []
for i in range(1,N+1):
    N0.append(i)
A = [int(i) for i in input().split()]
C = 0
for i in range(M):
    C = N0[A[i]-1]
    N0.remove(N0[A[i]-1])
    N0.insert(0,C)
print(C)