from sys import exit
def factorization(n):
    arr = []
    tmp = n
    for i in range(2,4):
        if tmp%i==0:
                cnt=0
                while(tmp%i==0):
                    cnt+=1
                    tmp//=i
                arr.append([i,cnt])
    for i in range(5, int(-(-tmp**0.5//1))+1,2):
        if tmp%i==0:
            cnt=0
            while tmp%i==0:
                cnt+=1
                tmp //= i
            arr.append([i, cnt])

    if tmp!=1:
        arr.append([tmp, 1])

    if arr==[]:
        arr.append([n, 1])

    return arr
N=int(input())
if N==1:
    print(0)
    exit()
ans=0
prime=factorization(N)
for i,cnt in prime:
    ans+=i*cnt
print(ans)