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 Python (3.4.3) (judge verdict: Time Limit Exceeded)

from collections import Counter
from functools import reduce

def modular_inverse(a, mod):
    return pow(a, mod-2, mod)

def prime_factorization(n):
    '''
    Trial division.
    Input: 
        n : a positive integer
    Output:
        a dictionary of #(each prime factors) of n,
    '''
    result = Counter()
    if n < 2:
        return result
    while n % 2 == 0:
        result[2] += 1
        n //= 2
    p = 3
    while p*p <= n:
        while n % p == 0:
            n //= p
            result[p] += 1
        p += 2
    if n > 1:
        result[n] += 1
    return result

MOD = 10**9 + 7

N = int(input())
*A, = map(int, input().split())
ans = 0
lcm = reduce(lambda x,y: x | y, [prime_factorization(a) for a in A])
L = 1
for x, y in lcm.items():
    L *= pow(x, y, MOD)
    L %= MOD
for a in A:
    ans += L * modular_inverse(a, MOD)
    ans %= MOD
print(ans)