def factorization(n):
    arr = [1]
    temp = n
    for i in range(2, int(-(-n**0.5//1))+1):
        if temp%i==0:
            cnt=0
            while temp%i==0:
                cnt+=1
                temp //= i
            arr.append(i)
    if temp!=1:
        arr.append(temp)
    if arr==[]:
        arr.append(n)
    arr.append(n)
    return arr

n = int(input())
factor = factorization(n)
print(sum(factor))