package no278; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner sc = new Scanner(System.in); long n = sc.nextLong(); long m = n % 2 == 0 ? n / 2 : n; long ans = 0; for(long i=1;i*i<=m;i++) { if (m % i == 0) { ans += i; if (i * i != m) { ans += m / i; } } } System.out.println(ans); } public static long gcd(long a,long b) { while(b!=0) { long r = a%b; a = b; b = r; } return a; } }