import math
N = int(input()) 
factor = []
tmp = int(math.sqrt(N)) + 1
list = range(2,tmp)
for num in list[::-1]:
    while N % num == 0:
        N //= num
        factor.append(num)
        factor.append(N)
    if not factor:
        factor.append(N)
        factor.append(0)
    else:
        pass
    break
f=sum(factor)-1
print(f)