n = int(input())
arr = []
ans = 0

#for i in range(1, n // 2 + 1):
for i in range(1, int(n**0.5 )+1):
    #print(i)
    if n % i == 0:
        arr.append(i)
        ans += i
        if i != n // i:
            arr.append(n//i)
            ans += n//i

#ans += n

#print(arr)
print(ans)