N = int(input())
A = list(map(int, input().split()))
S = set()
ans = 0
ct = 0
for a in A:
    if a not in S:
        S.add(a)
        ct += 1
    else:
        ans = max(ans, ct)
        ct = 1
        S.clear()
        S.add(a)
ans = max(ans,ct)
print(ans)