from heapq import *
from collections import *

N, K = map(int, input().split())
A = list(map(int, input().split()))
H = []
D = defaultdict(int)
for a in A:
    D[a] += 1
    
for k, v in D.items():
    heappush(H, (-v, k))
    
ans = set()
while K > 0:
    v, k = heappop(H)
    v = -v
    K -= v
    ans.add(k)
        
print(len(ans))