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()