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


double normal (void)
{
    double u1, u2;


    u1 = 1.0 - drand48 ( );
    u2 = 1.0 - drand48 ( );

    return sqrt (-2.0 * log (u1)) * cos (2 * M_PI * u2);
}


int main (int argc, char *argv [])
{
    double u1, u2;
    int i, n;


    n = (argc > 1 ? atoi (argv [1]) : 1);
    srand48 (time (NULL));

    for (i = 0; i < n; i ++)
	printf ("%g\n", normal ( ));

    return 0;
}