from collections import Counter

def findMinimumDistinct(A, N, K):
    mp = Counter(A)
    count = 0
    length = 0
    counts = []
    for i in mp:
        counts.append(mp[i])
    counts = sorted(counts)
    counts.reverse()

    for i in range(len(counts)):

        if (length >= K):
            break

        length += counts[i]
        count += 1

    print(count)

N,K = map(int,input().split())
A = list(map(int,input().split()))

findMinimumDistinct(A, N, K)