n,k=map(int,input().split())
P=list(map(int,input().split()))
l=[i for i in range(0,402)]
anss=[]

for x in l:
    ans=0
    for i in range(n):
        if l[i]>=x:
            ans+=1
    anss.append(ans)
ans=0
anss.sort()
for x in anss:
    if k>=x:
        ans=x
print(ans)