#!/usr/bin/perl

use strict;
use warnings;

use Algorithm::Graphs::TransitiveClosure qw /floyd_warshall/;

my $g;

while (<DATA>) {
    my ($from, $to) = split;
    $g -> {$from} -> {$to} = 1;
}

floyd_warshall $g;

while (my ($key, $value) = each %$g) {
    print "Recursion for function '$key'\n" if exists $g -> {$key} {$key};
}


__DATA__
aaa bbb
bbb ccc
bbb ddd
ccc ddd
ddd aaa
ddd eee