Squirrel Liss is interested in sequences. She also has preferences of integers. She thinks $*n*$ integers $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$ are good.
Now she is interested in good sequences. A sequence $*x*_{1}, *x*_{2}, ..., *x*_{*k*}$ is called good if it satisfies the following three conditions:
- The sequence is strictly increasing, i.e.
$*x*_{*i*} < *x*_{*i* + 1}$for each$*i*$$(1 ≤ *i* ≤ *k* - 1)$. - No two adjacent elements are coprime, i.e.
$*gcd*(*x*_{*i*}, *x*_{*i* + 1}) > 1$for each$*i*$$(1 ≤ *i* ≤ *k* - 1)$(where$*gcd*(*p*, *q*)$denotes the greatest common divisor of the integers$*p*$and$*q*$). - All elements of the sequence are good integers.
Find the length of the longest good sequence.
Input
The input consists of two lines. The first line contains a single integer $*n*$ ($1 ≤ *n* ≤ 10^{5}$) — the number of good integers. The second line contains a single-space separated list of good integers $*a*_{1}, *a*_{2}, ..., *a*_{*n*}$ in strictly increasing order ($1 ≤ *a*_{*i*} ≤ 10^{5}; *a*_{*i*} < *a*_{*i* + 1}$).
Output
Print a single integer — the length of the longest good sequence.
Note
In the first example, the following sequences are examples of good sequences: [2; 4; 6; 9], [2; 4; 6], [3; 9], [6]. The length of the longest good sequence is 4.
样例
5
2 3 4 6 9
4
9
1 2 3 5 6 7 8 9 10
4
题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。