#input of int(split by space)
def get_i()
  return gets.chomp.split(" ").map(&:to_i)
end
#input of float(split by space)
def get_f()
  return gets.chomp.split(" ").map(&:to_f)
end
#input of string(split by space)
def get()
  return gets.chomp.split(" ")
end
#input of string(split per one character)
def get_nsp()
  return gets.chomp.split("")
end
#yes or no decision
def yn_judge(bool,y="Yes",n="No")
  return bool ? y : n 
end
#create of array
def array(size1,init=nil,size2=-1)
  if size2==-1
      return Array.new(size1){init}
  else
      return Array.new(size2){Array.new(size1){init}}
  end
end

def max(a,b)
    return a>b ? a : b
end

def min(a,b)
    return a>b ? b : a
end

INF=Float::INFINITY

N=gets.to_i
class Edge
  attr_accessor:to,:from
  def initialize(from,to)
      @to=to
      @from=from
  end
end
$ans=0
def bfs(g)
  color=array(N,-1)
  ret=Array.new(N){Hash.new}
  que=[0]
  until que==[]
    p=que.shift
    c=1
    g[p].each do|e|
        next unless color[e.to]==-1
        c+=1 if color[p]==c
        color[e.to]=c
        ret[e.from][e.to]=c
        #ret[e.to][e.from]=c
        $ans=max($ans,c)
        c+=1
        que.push(e.to)
    end
  end
  return ret
end
g=Array.new(N){[]}
ab=array(N-1)
(N-1).times do|i|
  ab[i]=get_i.map{|x| x-=1}
  g[ab[i][0]].push(Edge.new(ab[i][0],ab[i][1]))
  #g[ab[i][1]].push(Edge.new(ab[i][1],ab[i][0]))
end
color=bfs(g)
puts $ans
#p color
ab.each do|a,b|
    puts color[a][b]
end