1942: Longest Ordered Subsequence

内存限制:128 MB 时间限制:1 S
题面:传统 评测方式:文本比较 上传者:
提交:1 通过:0

题目描述

A numeric sequence of ai is ordered if a1 < a2 < ... < aN. Let the subsequence of the given numeric sequence (a1, a2, ..., aN) be any sequence (ai1, ai2, ..., aiK), where 1 <= i1 < i2 < ... < iK <= N. For example, sequence (1, 7, 3, 5, 9, 4, 8) has ordered subsequences, e. g., (1, 7), (3, 4, 8) and many others. All longest ordered subsequences are of length 4, e. g., (1, 3, 5, 8).

Your program, when given the numeric sequence, must find the length of its longest ordered subsequence.

输入格式

The first line of input file contains the length of sequence N. The second line contains the elements of sequence - N integers in the range from 0 to 10000 each, separated by spaces. 1 <= N <= 1000

输出格式

Output file must contain a single integer - the length of the longest ordered subsequence of the given sequence.

输入样例 复制

7
1 7 3 5 9 4 8

输出样例 复制

4