#include <cstdio>
#include <cmath>
#include <iostream>

#define rep( i, n, m ) for (int i = ( n ); i < ( m ); i++)
#define rep_d( i, n, m ) for (int i = ( n ); i < ( m ); i--)

typedef unsigned long long lint;

int main( void ){
	lint n;
	std::cin >> n;
	if (n == 1){
		printf( "1\n" );
		return 0;
	}
	lint sum = 1 + n;
	lint max = std::sqrt( n ) + 1;
	lint a;
	for(lint i = 2; i < max; i++){
		a = ( lint )( n / i );
		if (n - i * a == 0){
			sum += i + a;
			if (i == max - 1)
				sum -= max - 1;
		}
	}
	std::cout << sum << std::endl;
	return 0;
}