N, K = map(int, input().split())
dic = dict()
A = list(map(int, input().split()))
for a in A:
    if a not in dic:
        dic[a] = 0
    dic[a] += 1
B = [dic[i] for i in dic]
B.sort(reverse=True)
s = 0
for i in range(len(B)):
    s += B[i]
    if s >= K:
        print(i + 1)
        exit()