// -*- mode: d -*-
// $Id: $
// http://www.bagley.org/~doug/shootout/

import string;

const int IM = 139968;
const int IA =   3877;
const int IC =  29573;

double
gen_random(double max)
{
    static int last = 42;
    return( max * (last = (last * IA + IC) % IM) / IM );
}

void
heapsort(int n, double *ra) {
    int i, j;
    int ir = n;
    int l = (n >> 1) + 1;
    double rra;

    for (;;) {
    if (l > 1) {
        rra = ra[--l];
    } else {
        rra = ra[ir];
        ra[ir] = ra[1];
        if (--ir == 1) {
        ra[1] = rra;
        return;
        }
    }
    i = l;
    j = l << 1;
    while (j <= ir) {
        if (j < ir && ra[j] < ra[j+1]) { ++j; }
        if (rra < ra[j]) {
        ra[i] = ra[j];
        j += (i = j);
        } else {
        j = ir + 1;
        }
    }
    ra[i] = rra;
    }
}

int main(char[][] args)
{
    int N = args.length < 2 ? 1 :string.atoi(args[1]);
    double[] ary;
    int i;
    
    ary = new double[N + 1];
    for (i=1; i<=N; i++)
       ary[i] = gen_random(1);

    heapsort(N, ary);

    printf("%.10g\n", ary[N]);
    return(0);
}