class Node:
    def __init__(self, val):
        self.l = None
        self.r = None
        self.v = val

class Tree:
    def __init__(self):
        self.root = None

    def getRoot(self):
        return self.root

    def add(self, val):
        if(self.root == None):
            self.root = Node(val)
        else:
            self._add(val, self.root)

    def _add(self, val, node):
        if(val < node.v):
            if(node.l != None):
                self._add(val, node.l)
            else:
                node.l = Node(val)
        else:
            if(node.r != None):
                self._add(val, node.r)
            else:
                node.r = Node(val)

    def find(self, val):
        if(self.root != None):
            return self._find(val, self.root)
        else:
            return None

    def _find(self, val, node):
        if(val == node.v):
            return node
        elif(val < node.v and node.l != None):
            self._find(val, node.l)
        elif(val > node.v and node.r != None):
            self._find(val, node.r)

    def deleteTree(self):
        # garbage collector will do this for us.
        self.root = None

    def printTree(self):
            if(self.root != None):
                self._printTree(self.root)

    def _printTree(self, node):
         if(node != None):
            self._printTree(node.l)
            print str(node.v) + ' '
            self._printTree(node.r)

    def hm_L_ch(self):
        if (self.root != None):
            return self._hm_ch(self.root.l, k = -1)
        else: return 0;

    def _hm_ch(self, node, k):
        if(node != None):
            k = k + 1
            self._hm_ch(node.l, k)
            self._hm_ch(node.r, k)
            return k
        else: return None


N = input()

a = []

tree = Tree()
i = 0
while i < N:
    k = input()
    tree.add(k)
    i = i + 1

print tree.hm_L_ch()
#tree.printTree()
#print (tree.find(3)).v
#print tree.find(10)
#tree.deleteTree()
#tree.printTree()