#P2533. Longest Ordered Subsequence

    ID: 1534 传统题 1000ms 256MiB 尝试: 1 已通过: 1 难度: 10 上传者: 标签>动态规划难度普及/提高-Northeastern Europe 2002Far-Eastern Subregion

Longest Ordered Subsequence

Description

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.

Input

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

Output

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

7
1 7 3 5 9 4 8
4

Source

Northeastern Europe 2002, Far-Eastern Subregion