from collections import defaultdict
N, K = map(int, input().split())
A = list(map(int, input().split()))
d = defaultdict(int)
for i in A:
    d[i] += 1
t = sorted([(j, i) for i, j in d.items()], reverse=True)
ans = 0
for j, i in t:
    K -= j
    ans += 1
    if K <= 0:
        break
print(ans)