n=gets.to_i+1
a=[0]+gets.split.map(&:to_i)+[0]
l=(0..n).map{[0]*3005}
r=(0..n).map{[0]*3005}
(1..n).each{|w|(0..n-w).each{|i|s=a[i]-a[i+w];x=l[w-1][i+1];y=r[w-1][i];l[w][i]=s>0?y<x ?x:y+1:x;r[w][i]=s<0?x<y ?y:x+1:y}}
p [l[n][0],r[n][0]].max