import sys, math
input = lambda: sys.stdin.readline()[:-1]
def MI(): return map(int, input().split())
inf = 10**18
from collections import *

n,k = MI()
a = list(MI())

cnt = Counter(a)
cnt = sorted(cnt.items(), key=lambda x:x[1], reverse=True)

now = 0
ans = 0
for key, value in cnt:
    if now >= k:
        break
    now += value
    ans += 1
print(ans)