#!/usr/bin/perl

use warnings;
use strict;

sub fib {
    my $n = shift;
    if ($n < 0) {
        return "Error";
    }
    if ($n == 0) {
        return 0;
    }
    if ($n == 1 || $n == 2) {
        return 1;
    }
    return fib($n -1) + fib($n - 2);
}

my $i;
for ($i = 0; $i <= 15; $i++) {
    print fib($i) . "\n";
}