import math
N = int(input())
if N == 1:
    print(1)
    exit(0)

P = [1,N]
for k in range(2,math.floor(math.sqrt(N))+1):
    if N % k == 0:
        if k*k == N:
            P.append(k)
        else:
            P.append(k)
            P.append(N//k)
print(sum(P))