'use strict';

process.stdin.resume();
process.stdin.setEncoding('utf-8');
// process.stdin.setEncoding('ascii');
let inputString: string = '';
let inputLines: string[] = [];
let currentLine: number = 0;
process.stdin.on('data', function(inputStdin: string): void {
    inputString += inputStdin;
});

process.stdin.on('end', function(): void {
    inputLines = inputString.split(/\s/);
    inputString = '';
    solution();
});

function readLine(): string {
    return inputLines[currentLine++];
}

class TreeNode {
    data:number;
    left:null|TreeNode;
    right:null|TreeNode;
    constructor(data:number){
    this.data = data;
    this.left = null;
    this.right = null;
    }
}

class Tree {
    root:TreeNode|null;
    constructor() {
    this.root = null;
    }
    insert(node:TreeNode, data:number) {
        if (node == null){
            node = new TreeNode(data);
        }
        else if (data < node.data){
            node.left  = this.insert(node.left, data);
        }
        else{
            node.right = this.insert(node.right, data);   
        }

        return node;
    }
}


// This is a "method-only" submission.
// You only need to complete this method.

function treeHeight(root:TreeNode):string {
	return "Your solution in here";

}


function solution() {

    var tree = new Tree();
    var n = parseInt(readLine());

    for (var i=0; i<n; i++) {
        var m = parseInt(readLine());
        tree.root = tree.insert(tree.root, m);
    }

    var height = treeHeight(tree.root);
    process.stdout.write(height);
}