#include <iostream>
#include <iomanip>


int main()
{
long double D1 = 3;
long double pi = 1 - (1 / D1);
int i = 3;
int calcs;

std::cout << "How many times to run loop?\n";
std::cin >> calcs;

for (i = 0; i<calcs; i++){
    D1 = D1 + 2;
    pi = pi + (1 / D1);
    D1 = D1 + 2;
    pi = pi - (1 / D1);
    std::cout << "1/4 Pi is equal to: " << std::setprecision(9) << pi << "\n";
}
pi = pi * 4;
std::cout << std::setprecision(9) << "Final pi value =" << pi << "\n";
return 0;
}