# 完全全探索でO(N x max(pi))
# あえてcnt部をbisect

from bisect import *

N, K = map(int, input().split())
P = list(map(int, input().split()))
P.sort()

ans = 0
for B in range(401):
    cnt = N - bisect_left(P,B)
    if cnt <= K:
        ans = max(ans,cnt)

print(ans)