import bisect import copy import decimal import fractions import heapq import itertools import math import random import sys import time from collections import Counter,deque,defaultdict from functools import lru_cache,reduce from heapq import heappush,heappop,heapify,heappushpop,_heappop_max,_heapify_max def _heappush_max(heap,item): heap.append(item) heapq._siftdown_max(heap, 0, len(heap)-1) def _heappushpop_max(heap, item): if heap and item < heap[0]: item, heap[0] = heap[0], item heapq._siftup_max(heap, 0) return item from math import gcd as GCD read=sys.stdin.read readline=sys.stdin.readline readlines=sys.stdin.readlines write=sys.stdout.write def Divisors(N): divisors=[] for i in range(1,N+1): if i**2>=N: break elif N%i==0: divisors.append(i) if i**2==N: divisors+=[i]+[N//i for i in divisors[::-1]] else: divisors+=[N//i for i in divisors[::-1]] return divisors N=int(readline()) ans=sum(Divisors(GCD(N,N*(N-1)//2))) print(ans)