#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define M_PI 3.14159265

int main() {
    double a, b, s, x[4], y[4], r, true_value;
    int count, m, n;

    x[0] = 1.0; y[0] = 0.0;
    x[1] = 0.0; y[1] = 1.0;
    x[2] = -1.0; y[2] = 0.0;
    x[3] = 0.0; y[3] = -1.0;

    r = 1.0;  
    true_value = (M_PI - pow(3, 1.5) + 3) / 3.0;  

    for (n = 10; n < 100000; n *= 5) {
        count = 0;
        s = 0.0;

        for (m = 0; m < n; m++) {
            a = (double)rand() / RAND_MAX * 2.0 - 1.0;  
            b = (double)rand() / RAND_MAX * 2.0 - 1.0;  

            int in_all_circles = 1;
            for (int i = 0; i < 4; i++) {
                double dist = (a - x[i]) * (a - x[i]) + (b - y[i]) * (b - y[i]);
                if (dist >= r) {
                    in_all_circles = 0;
                    break;
                }
            }

            if (in_all_circles) {
                s += 1.0;
            }
            count++;
        }

        s /= count;  
        s *= 4.0;    

        printf("%d\t%f\n", n, fabs(s - true_value));
    }

    return 0;
}