from bisect import bisect_left
N=int(input())
A=[int(input()) for _ in range(N)]
A.sort()

ar=[-1]
for i in range(N):
    b=bisect_left(ar,A[i]-1)
    if b>0:
        ar[b-1]=A[i]
    else:
        ar.append(A[i])
print(len(ar))