import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,copy,functools
import random

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**10
mod = 10**9+7
dd = [(-1,0),(0,1),(1,0),(0,-1)]
ddn = [(-1,0),(-1,1),(0,1),(1,1),(1,0),(1,-1),(0,-1),(-1,-1)]

def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(): return [list(map(int, l.split())) for l in sys.stdin.readlines()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)
def pe(s): return print(str(s), file=sys.stderr)

def divisions(n):
    sq = int(math.sqrt(n)+1)
    ss = 30030
    a = [None] * (ss)
    a[0] = 1
    t = 1
    for i in range(2,ss):
        if not a[i] is None:
            continue
        if t * i > ss:
            break
        t *= i
        for j in range(i*2,ss,i):
            a[j] = 1
    a = [i for i in range(t) if a[i] is None]
    d = collections.defaultdict(int)
    for i in a[1:]:
        while n % i == 0:
            n //= i
            d[i] += 1

    for j in range(1,sq//t+2):
        if j > n:
            break
        for ii in a:
            i = t*j+ii
            while n % i == 0:
                n //= i
                d[i] += 1
    r = [1]
    for k, v in d.items():
        for c in r[:]:
            for i in range(1,v+1):
                r.append(c*(k**i))

    return sorted(r)

def main():
    n = I()
    if n == 1:
        return 0
    ds = divisions(n)
    # print(ds)
    r = 0
    u = set()
    mk = ds[1]
    for k in ds:
        if k < 2:
            continue
        for a in range(1,mk):
            t = k - a
            if t in u:
                continue
            u.add(t)
            if n // t == n % t or True:
                r += t

    return r


print(main())




### FIXED CODE ###

import math,string,itertools,fractions,heapq,collections,re,array,bisect,sys,copy,functools
import random

sys.setrecursionlimit(10**7)
inf = 10**20
eps = 1.0 / 10**10
mod = 10**9+7
dd = [(-1,0),(0,1),(1,0),(0,-1)]
ddn = [(-1,0),(-1,1),(0,1),(1,1),(1,0),(1,-1),(0,-1),(-1,-1)]

def LI(): return list(map(int, sys.stdin.readline().split()))
def LLI(): return [list(map(int, l.split())) for l in sys.stdin.readlines()]
def LI_(): return [int(x)-1 for x in sys.stdin.readline().split()]
def LF(): return [float(x) for x in sys.stdin.readline().split()]
def LS(): return sys.stdin.readline().split()
def I(): return int(sys.stdin.readline())
def F(): return float(sys.stdin.readline())
def S(): return input()
def pf(s): return print(s, flush=True)
def pe(s): return print(str(s), file=sys.stderr)

def divisions_(n):
    sq = int(math.sqrt(n)+1)
    ss = 30030
    a = [None] * (ss)
    a[0] = 1
    t = 1
    for i in range(2,ss):
        if not a[i] is None:
            continue
        if t * i > ss:
            break
        t *= i
        for j in range(i*2,ss,i):
            a[j] = 1
    a = [i for i in range(t) if a[i] is None]
    d = collections.defaultdict(int)
    for i in a[1:]:
        while n % i == 0:
            n //= i
            d[i] += 1

    for j in range(1,sq//t+2):
        if j > n:
            break
        for ii in a:
            i = t*j+ii
            while n % i == 0:
                n //= i
                d[i] += 1
    r = [1]
    for k, v in d.items():
        for c in r[:]:
            for i in range(1,v+1):
                r.append(c*(k**i))

    return sorted(r)
def divisions(n):
    sq = int(math.sqrt(n)+1)
    d = collections.defaultdict(int)
    while n % 2 == 0:
        n //= 2
        d[2] += 1
    i = 3
    while n > 1 and sq >= i:
        if n % i == 0:
            n //= i
            d[i] += 1
        else:
            i += 2

    if n > 1:
        d[n] += 1

    r = [1]
    for k, v in d.items():
        for c in r[:]:
            for i in range(1,v+1):
                r.append(c*(k**i))

    return sorted(r)

def main():
    n = I()
    ds = divisions(n)
    # print(ds)
    r = 0
    u = set([0])
    mk = ds[0]
    if len(ds) > 1:
        mk = ds[1]
    for k in ds:
        if k < 2:
            continue
        for a in range(1,mk):
            t = k - a
            if t in u:
                continue
            u.add(t)
            if n // t == n % t:
                r += t

    return r


print(main())