import sys
#sys.setrecursionlimit(10 ** 6)
INF = float('inf')
#10**20,2**63に変えるのもあり
MOD = 10**9 + 7
MOD2 = 998244353
from collections import defaultdict
def ceil(A,B):
    return -(-A//B)
def solve():
    def II(): return int(sys.stdin.readline())
    def LI(): return list(map(int, sys.stdin.readline().split()))
    def LC(): return list(input())
    def IC(): return [int(c) for c in input()]
    def MI(): return map(int, sys.stdin.readline().split())
    N,K = MI()
    A = LI()
    C = defaultdict(lambda:0)
    Ans = INF
    S = 0
    for i in range(K):
        C[A[i]]+=1
        if(C[A[i]]==1):S+=1
    Ans = min(Ans,S)
    for i in range(N-K):
        C[A[i+K]]+=1
        if(C[A[i+K]]==1):S+=1
        C[A[i]]-=1
        if(C[A[i]]==0):S-=1
        Ans = min(Ans,S)
    print(Ans)
    return
solve()