#P11626. Seven GCD Strikes

    ID: 13720 Type: Default 1000ms 256MiB

Seven GCD Strikes

Seven GCD Strikes

In this problem, you are given an array (A) of length (n). You need to compute the value of the following expression modulo (998244353): [ S = \sum_{1 \le a < b < c < d < e < f < g \le n} \Bigl( \gcd(A_1, A_2, \dots, A_a) + \gcd(A_{a+1}, \dots, A_b) + \gcd(A_{b+1}, \dots, A_c) + \gcd(A_{c+1}, \dots, A_d) + \gcd(A_{d+1}, \dots, A_e) + \gcd(A_{e+1}, \dots, A_f) + \gcd(A_{f+1}, \dots, A_g) \Bigr ) ] Here, (\gcd(A_l, A_{l+1}, \dots, A_r)) denotes the greatest common divisor of the numbers (A_l, A_{l+1}, \dots, A_r).

Note: The seven indices (a,b,c,d,e,f,g) satisfy (1 \le a < b < c < d < e < f < g \le n), which partitions the array into 7 non-empty contiguous segments. Your task is to compute (S \bmod 998244353).

inputFormat

The first line contains a single integer (n) (the length of the array). The second line contains (n) space-separated integers, representing the array (A).

outputFormat

Output a single integer denoting the value of the given expression modulo (998244353).

sample

7
1 1 1 1 1 1 1
7