from collections import *
from itertools import *
from functools import *
from heapq import *
import sys,math
input = sys.stdin.readline

N,K = map(int,input().split())
A = list(map(int,input().split()))
C = Counter(A)
V = list(C.values())
V.sort(reverse=True)
cnt = 0
x = 0
while x<K:
    x += V[cnt]
    cnt += 1
print(cnt)