#include <iostream>
#include "cmath"

using namespace std;

int main()
{
	setlocale (LC_ALL, "rus_rus.1251");
	long double e, z = 0, sum = 0;
	cout << "Введите точность...\n";
	cin >> e;

	for (int n = 1; abs(z) < (e/10) ; n++)
		{
			z = (log(n)*log(n)*log(n)) / (n*(sqrtl(5*n+1)));
			sum = sum + z;
		}
	cout <<"Сумма = "<< sum <<endl;

return 0;
}