import sys

sys.setrecursionlimit(10 ** 6)
from bisect import *
from collections import *
from heapq import *

int1 = lambda x: int(x) - 1
p2D = lambda x: print(*x, sep="\n")
def II(): return int(sys.stdin.readline())
def SI(): return sys.stdin.readline()[:-1]
def MI(): return map(int, sys.stdin.readline().split())
def MI1(): return map(int1, sys.stdin.readline().split())
def MF(): return map(float, sys.stdin.readline().split())
def LI(): return list(map(int, sys.stdin.readline().split()))
def LI1(): return list(map(int1, sys.stdin.readline().split()))
def LF(): return list(map(float, sys.stdin.readline().split()))
def LLI(rows_number): return [LI() for _ in range(rows_number)]
dij = [(0, 1), (1, 0), (0, -1), (-1, 0)]
# (底,指数)を返す
# 18=2**1 * 3**2なので[(2,1),(3,2)]
def PrimeFactorization(x):
    def plist(x):
        if x < 2: return []
        if x & 1 == 0: return [2] + plist(x // 2)
        for p in range(3, x + 1, 2):
            if x % p == 0: return [p] + plist(x // p)
            if p ** 2 > x: return [x]

    pl = plist(x)
    pp, ee = [], []
    for p in pl:
        if not pp or p != pp[-1]:
            pp += [p]
            ee += [0]
        ee[-1] += 1
    return [(p, e) for p, e in zip(pp, ee)]

def gcd(a, b):
    while b: a, b = b, a % b
    return a

def expsum(p,e):
    return (pow(p,e+1)-1)//(p-1)

def main():
    n=II()
    print(sum(expsum(p,e) for p,e in PrimeFactorization(gcd(n,(n-1)*n//2))))

main()