Problem:
Score : 500 points

Problem Statement

Given are N positive integers A_1,...,A_N.

Consider positive integers B_1, ..., B_N that satisfy the following condition.

Condition: For any i, j such that 1 \leq i < j \leq N, A_i B_i = A_j B_j holds.

Find the minimum possible value of B_1 + ... + B_N for such B_1,...,B_N.

Since the answer can be enormous, print the sum modulo (10^9 +7).

Constraints

1 \leq N \leq 10^4

1 \leq A_i \leq 10^6

All values in input are integers.

Input

Input is given from Standard Input in the following format:

N
A_1 ... A_N

Output

Print the minimum possible value of B_1 + ... + B_N for B_1,...,B_N that satisfy the condition, modulo (10^9 +7).

Sample Input 1

3
2 3 4

Sample Output 1

13

Let B_1=6, B_2=4, and B_3=3, and the condition will be satisfied.

Sample Input 2

5
12 12 12 12 12

Sample Output 2

5

We can let all B_i be 1.

Sample Input 3

3
1000000 999999 999998

Sample Output 3

996989508

Print the sum modulo (10^9+7).

Solution in Rust (1.42.0) (judge verdict: Accepted)

#[allow(unused_imports)]
use itertools::Itertools;
#[allow(unused_imports)]
use num::*;
use proconio::input;
#[allow(unused_imports)]
use proconio::marker::*;
#[allow(unused_imports)]
use std::collections::*;

#[derive(Copy, Clone, Debug, Eq, PartialEq)]
pub struct ModInt(u32);

impl ModInt {
    pub const MOD: u32 = 1_000_000_007;

    pub fn inv(self) -> Self {
        if self.0 == 0 {
            panic!();
        }
        self.pow(Self::MOD - 2)
    }

    pub fn one() -> Self {
        Self(1)
    }

    pub fn pow(self, e: u32) -> Self {
        if e == 0 {
            return Self::new(1);
        }
        let mut res = self.pow(e >> 1);
        res *= res;
        if e & 1 == 1 {
            res *= self;
        }
        res
    }

    pub fn zero() -> Self {
        Self(0)
    }

    fn new(n: i64) -> Self {
        let mut n = n % (Self::MOD as i64);
        if n.is_negative() {
            n += Self::MOD as i64;
        }
        Self(n as u32)
    }
}

impl From<i32> for ModInt {
    fn from(n: i32) -> Self {
        ModInt::from(n as i64)
    }
}

impl From<i64> for ModInt {
    fn from(n: i64) -> Self {
        Self::new(n)
    }
}

impl From<isize> for ModInt {
    fn from(n: isize) -> Self {
        ModInt::from(n as i64)
    }
}

impl From<u32> for ModInt {
    fn from(n: u32) -> Self {
        ModInt::from(n as u64)
    }
}

impl From<u64> for ModInt {
    fn from(n: u64) -> Self {
        Self::new(n as i64)
    }
}

impl From<usize> for ModInt {
    fn from(n: usize) -> Self {
        ModInt::from(n as u64)
    }
}

impl Into<i32> for ModInt {
    fn into(self) -> i32 {
        self.0 as i32
    }
}

impl Into<i64> for ModInt {
    fn into(self) -> i64 {
        self.0 as i64
    }
}

impl Into<isize> for ModInt {
    fn into(self) -> isize {
        self.0 as isize
    }
}

impl Into<u32> for ModInt {
    fn into(self) -> u32 {
        self.0
    }
}

impl Into<u64> for ModInt {
    fn into(self) -> u64 {
        self.0 as u64
    }
}

impl Into<usize> for ModInt {
    fn into(self) -> usize {
        self.0 as usize
    }
}

impl std::fmt::Display for ModInt {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        write!(f, "{}", self.0)
    }
}

impl std::ops::Add for ModInt {
    type Output = Self;

    fn add(self, rhs: Self) -> Self {
        Self::new((self.0 + rhs.0) as i64)
    }
}

impl std::ops::AddAssign for ModInt {
    fn add_assign(&mut self, rhs: Self) {
        *self = *self + rhs;
    }
}

impl std::ops::Div for ModInt {
    type Output = Self;

    fn div(self, rhs: Self) -> Self {
        self * rhs.inv()
    }
}

impl std::ops::DivAssign for ModInt {
    fn div_assign(&mut self, rhs: Self) {
        *self = *self / rhs;
    }
}

impl std::ops::Mul for ModInt {
    type Output = Self;

    fn mul(self, rhs: Self) -> Self {
        Self::new((self.0 as i64) * (rhs.0 as i64))
    }
}

impl std::ops::MulAssign for ModInt {
    fn mul_assign(&mut self, rhs: Self) {
        *self = *self * rhs;
    }
}

impl std::ops::Sub for ModInt {
    type Output = Self;

    fn sub(self, rhs: Self) -> Self {
        Self::new((self.0 as i64) - (rhs.0 as i64))
    }
}

impl std::ops::SubAssign for ModInt {
    fn sub_assign(&mut self, rhs: Self) {
        *self = *self - rhs;
    }
}

pub fn prime_factor(n: u64) -> std::collections::HashMap<u64, u64> {
    if n < 2 {
        return std::collections::HashMap::new();
    }
    let mut res = std::collections::HashMap::new();
    let mut n = n;
    let mut i = 2;
    while i * i <= n {
        while n % i == 0 {
            let c = res.entry(i).or_insert(0);
            *c += 1;
            n /= i;
        }
        i += 1;
    }
    if n != 1 {
        res.insert(n, 1);
    }
    res
}

fn solve() {
    input! {
        n: usize,
        av: [u64; n]
    };

    let pfv = av.iter().map(|&a| prime_factor(a)).collect::<Vec<_>>();
    let lcm_pf = pfv
        .iter()
        .fold(HashMap::new(), |mut acc: HashMap<u64, u64>, pf| {
            for (p, c) in pf {
                if let Some(ac) = acc.get_mut(p) {
                    *ac = (*ac).max(*c);
                } else {
                    acc.insert(*p, *c);
                }
            }
            acc
        });
    let lcm = lcm_pf.into_iter().fold(ModInt::one(), |acc, (p, c)| {
        acc * ModInt::from(p).pow(c as u32)
    });
    let mut res = ModInt::zero();
    for a in av {
        res += lcm / ModInt::from(a);
    }
    println!("{}", res);
}

fn main() {
    std::thread::Builder::new()
        .name("big stack size".into())
        .stack_size(256 * 1024 * 1024)
        .spawn(|| {
            solve();
        })
        .unwrap()
        .join()
        .unwrap();
}