#include <stdio.h>
#include <unistd.h>
#include <stdlib.h>
#include <sys/wait.h>

#define RADIUS 0.5

int main(int argc, char *argv[])
{
    if (argc < 2) {
        printf("Not enough args\n");
        return 0;
    }
    int iters = atoi(argv[1]);
    int i, count = 0;
    double x, y;
    for (i = 0; i < iters; i++)
    {
        x = RADIUS - drand48();
        y = RADIUS - drand48();
        if (x * x + y * y < RADIUS * RADIUS) count++;
    }
    printf("%f\n", 4.0 * (double)count / (double)iters);

    return 0;
}