N, K = map(int, input().split())
A = list(map(int, input().split()))
cnt = [0]*(N + 1)
for a in A:
    cnt[a] += 1
data = []
for i in range(1, N + 1):
    if cnt[i] != 0:
        data.append((cnt[i], i))
data.sort()

total = 0
distinct_nums = 0
while data:
    c, num = data.pop()
    if total + c < K:
        distinct_nums += 1
        total += c
    else:
        distinct_nums += 1
        break
print(distinct_nums)