class Family:
    def __init__(self, id):
        self.__id = id
        self.__parents = []
        self.__children = []
    def getParents(self):
        return self.__parents
    def getId(self):
        return self.__id
    def addParent(self, parent):
        self.__parents = set(parent.getParents()) | set(self.__parents)
        self.__parents = list(set([parent]) | self.__parents)
    def distance(self, guest):
        sameParents = list(set(self.getParents()) & set(guest.getParents()))
        try:
            sameParent = sameParents[0]
        except IndexError:
            """TOP"""
            return abs(len(self.getParents()) - len(guest.getParents()))
        for i in sameParents:
            if len(i.getParents()) > len(sameParent.getParents()):
                sameParent = i
        return abs(len(self.getParents()) - len(sameParent.getParents())) + abs(len(guest.getParents()) - len(sameParent.getParents()))
    def refresh(self):
        for i in self.getParents():
            self.addParent(i)

def main():
    memberCount = int(input())
    families = []
    commandCount = memberCount - 1
    while (memberCount > 0):
        families.append(Family(len(families)))
        memberCount -= 1
    while (commandCount > 0):
        command = [int(i) for i in input().split(" ")]
        families[command[1]].addParent(families[command[0]])
        commandCount -= 1
    for i in families:
        i.refresh()
    maxDistance = 0
    for mainIndex in list(range(len(families) - 1)):
        guestIndex = mainIndex + 1
        while(guestIndex < len(families)):
            if families[mainIndex].distance(families[guestIndex]) > maxDistance:
                maxDistance = families[mainIndex].distance(families[guestIndex])
            guestIndex += 1
    print(maxDistance)
main()