tree height

 from collections import defaultdict

def insert(tree,current,value):

  if value < current:

    if not tree[current][0]:

      tree[current][0]=value

    else:

      insert(tree,tree[current][0],value)

  else:

    if not tree[current][1]:

      tree[current][1]=value

    else:

      insert(tree,tree[current][1],value)

      

def height(tree,node):

  if not node:

    return 0

  l_height = height(tree,tree[node][0])

  r_height = height(tree,tree[node][1])

  return max(l_height,r_height)+1

inputs = list(map(int,input().split()))

tree = defaultdict(lambda:[None,None])

root = inputs[0]

for value in inputs[1:]:

  insert(tree,root,value)

print(height(tree,root))

    

# STDIN

# 3 1 2 4 5

# Output:

# 3