Problem:
Score : 400 points

Problem Statement

Given is a positive integer N. Consider repeatedly applying the operation below on N:

First, choose a positive integer z satisfying all of the conditions below:

z can be represented as z=p^e, where p is a prime number and e is a positive integer;

z divides N;

z is different from all integers chosen in previous operations.

Then, replace N with N/z.

Find the maximum number of times the operation can be applied.

Constraints

All values in input are integers.

1 \leq N \leq 10^{12}

Input

Input is given from Standard Input in the following format:

N

Output

Print the maximum number of times the operation can be applied.

Sample Input 1

24

Sample Output 1

3

We can apply the operation three times by, for example, making the following choices:

Choose z=2 (=2^1). (Now we have N=12.)

Choose z=3 (=3^1). (Now we have N=4.)

Choose z=4 (=2^2). (Now we have N=1.)

Sample Input 2

1

Sample Output 2

0

We cannot apply the operation at all.

Sample Input 3

64

Sample Output 3

3

We can apply the operation three times by, for example, making the following choices:

Choose z=2 (=2^1). (Now we have N=32.)

Choose z=4 (=2^2). (Now we have N=8.)

Choose z=8 (=2^3). (Now we have N=1.)

Sample Input 4

1000000007

Sample Output 4

1

We can apply the operation once by, for example, making the following choice:

z=1000000007 (=1000000007^1). (Now we have N=1.)

Sample Input 5

997764507000

Sample Output 5

7

Solution in Python (3.8.2) (judge verdict: Time Limit Exceeded)

import random

def is_prime(q,k=50):
    q = abs(q)
    #計算するまでもなく判定できるものははじく
    if q == 2: return True
    if q < 2 or q&1 == 0: return False

    #n-1=2^s*dとし（但しaは整数、dは奇数)、dを求める
    d = (q-1)>>1
    while d&1 == 0:
        d >>= 1
    
    #判定をk回繰り返す
    for i in range(k):
        a = random.randint(1,q-1)
        t = d
        y = pow(a,t,q)
        #[0,s-1]の範囲すべてをチェック
        while t != q-1 and y != 1 and y != q-1: 
            y = pow(y,2,q)
            t <<= 1
        if y != q-1 and t&1 == 0:
            return False
    return True

n = int(input())
count = 0
zlist = []
N = n

while True:
    for i in range(n):
        for e in range(1, 10):
            #print('i=',i,'e=', e)
            if is_prime(i) and N % (i**e) == 0 and i**e not in zlist:
                z = i ** e
                zlist.append(i**e)
                N /= z     
                count += 1
                #print('i=', i, 'n=', N, 'z=', z, 'zlist=',zlist,'count=', count)

    if i == n - 1:
        break

print(count)