#include <iostream>
#include <cstdlib>
#include <ctime>

using namespace std;

double pi(unsigned N)
{
    double x, y;
    unsigned n = 0;

    for(unsigned i = 0; i < N; ++i)
    {
        x = 1.0 * (rand() - 1) / 32766;
        y = 1.0 * (rand() - 1) / 32766;

        if(x * x + y * y <= 1)
            ++n;
    }

    return 4.0 * n / N;
}

int main()
{
    srand(static_cast<unsigned>(time(nullptr)));

    cout << pi(100000000) << endl;
    return 0;
}