import collections
N,K = map(int, input().split())
A = list(map(int, input().split())) 
CA = collections.Counter(A)
L = []
for k in CA.values():
    L.append(k)
sorted(L)
ans = 0
for i,l in enumerate(L):
    K-=l    
    if K<=0:
        print(i+1)
        exit()