import sys
sys.setrecursionlimit(400000)
class SegTree:
  def __init__(self,op,e,v):
    self._op=op
    self._e=e
    
    if isinstance(v,int):
      v=[e]*v
    
    self._n=len(v)
    self._log=self.ceil2()
    self._size=1<<self._log
    self._d=[e]*(2*self._size)
    
    for i in range(self._n):
      self._d[self._size+i]=v[i]
    for i in range(self._size-1,0,-1):
      self._update(i)
    return
  
  def ceil2(self):
    x=0
    while (1<<x)<self._n:
      x+=1
    return x
    
  def set(self,p,x):
    p+=self._size
    self._d[p]=x
    for i in range(1,self._log+1):
      self._update(p>>i)
    return
    
  def get(self,p):
    return self._d[p+self._size]
    
  def prod(self,left,right):
    sml=self._e
    smr=self._e
    left+=self._size
    right+=self._size
    while left<right:
      if left&1:
        sml=self._op(sml,self._d[left])
        left+=1
      if right&1:
        right-=1
        smr=self._op(self._d[right],smr)
      left>>=1
      right>>=1
    return self._op(sml,smr)
    
  def all_prod(self):
    return self._d[1]
  
  def max_right(self,left,target):
    self.target=target
    if left==self._n:
      return self._n
    left+=self._size
    sm=self._e
    
    first=True
    while first or (left & -left)!=left:
      first=False
      while left%2==0:
        left>>=1
      if not self._f(self._op(sm,self._d[left])):
        while left<self._size:
          left*=2
          if self._f(self._op(sm,self._d[left])):
            sm=self._op(sm,self._d[left])
            left+=1
        return left-self._size
      sm=self._op(sm,self._d[left])
      left+=1
    return self._n
    
  def min_left(self,right,target):
    self.target=target
    if right==0:
      return 0
    
    right+=self._size
    sm=self._e
    
    first=True
    while first or (right&-right)!=right:
      first=False
      right-=1
      while right>1 and right%2:
        right>>=1
      if not self._f(self._op(self._d[right],sm)):
        while right<self._size:
          right=2*right+1
          if self._f(self._op(self._d[right],sm)):
            sm=self._op(self._d[right],sm)
            right-=1
        return right+1-self._size
      sm=self._op(self._d[right],sm)
    return 0
  
  def _update(self,k):
    self._d[k]=self._op(self._d[2*k],self._d[2*k+1])
    return

  def _f(self,u):
    return u<self.target


pin=sys.stdin.readline
def main():
  N=int(pin())
  Graph=[[]for i in range(N)]
  checked=[False]*N
  for i in range(N-1):
    x,y=map(int,pin().split())
    Graph[x-1].append(y-1)
    Graph[y-1].append(x-1)
  seg=SegTree(max,[-1,-1],N)
  searched=[0]
  def dfs(i):
    pre=searched[0]
    checked[i]=True
    for to in Graph[i]:
      if not checked[to]:
        cnt=dfs(to)
        seg.set(searched[0],[cnt,searched[0]])
        searched[0]+=1
    res=1
    for j in range(2):
      tmp=seg.prod(pre,searched[0])
      if tmp[0]==-1:
        break
      res+=tmp[0]
      seg.set(tmp[1],[-1,-1])
    return res
  ans=dfs(0)
  print(ans)
  return

main()