N = int(input())
nums = [int(x) for x in input().split()]
num_type = set(nums)
if len(num_type) == N:
    newly = N
else:
    newly = 0
    current = None
    while nums:
        current = nums.pop(0)
        if current in nums:
            idxs = []
            for idx,num in enumerate(nums):
                if num == current:
                    idxs.insert(0,idx)
            for idx in idxs:
                del nums[idx]
        else:
            newly +=1

print(newly)