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

dict = {}

for i,v in enumerate(A):
    if v not in dict:
        dict[v] = 1
    else:
        dict[v] += 1

tmp = []

for ind,val in dict.items():
    tmp.append(val)

tmp.sort()
tmp.reverse()

ans = 0
for i,v in enumerate(tmp):
    K-=v
    if K <= 0:
        print(i+1)
        exit()