BIT=[0]*1000001
def add x,v;(BIT[x]+=v;x+=x&-x)while BIT[x];end
def sum x;s=0;(s+=BIT[x];x&=x-1)while x>0;s;end
l=[]
_,k,*t=$<.read.split.map &:to_i
cnt=Hash.new{0}
all=0
t.map{|w|
  if w>0
    if all-sum(w-1)<k
      cnt[w]+=1
      all+=1
      add(w,1)
    end
  else
    if cnt[-w]>0
      cnt[-w]-=1
      all-=1
      add(-w,-1)
    end
  end
}
p all