题目描述
Problem Statement
We have a directed graph G with N vertices numbered 1 to N.
Between two vertices $i,j (1 \leq i,j \leq N, i \neq j),$ there is an edge $i \to$ j if and only if both of the following conditions are satisfied.
- i<j
- $\mathrm{gcd}(i,j)>1$
Additionally, each vertex has an associated value: the value of Vertex i is A_i.
Consider choosing a set s of vertices so that the following condition is satisfied.
- For every pair (x,y) (x<y) of different vertices in s, y is unreachable from x in G.
Find the maximum possible total value of vertices in s.
Input
Input is given from Standard Input in the following format:
N
$A_1 A_2 \cdots A_N$
Output
Print the answer.
Constraints
- $1 \leq N \leq 10^6$
- $1 \leq A_i \leq 10^9$
- All values in input are integers.
Sample Input 1
6
1 1 1 1 1 1
Sample Output 1
4
We should choose s={1,2,3,5}.
Sample Input 2
6
1 2 1 3 1 6
Sample Output 2
8
We should choose s={1,5,6}.
Sample Input 3
20
40 39 31 54 27 31 80 3 62 66 15 72 21 38 74 49 15 24 44 3
Sample Output 3
343
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分