import sys
read = sys.stdin.buffer.read
readline = sys.stdin.buffer.readline
readlines = sys.stdin.buffer.readlines

import numpy as np

N = int(read())

x = np.arange(1, 10**6+10, dtype=np.int64)

div = x[N%x==0]
div = np.union1d(div, N//div)

answer = div.sum()
print(answer)