#! /usr/bin/perl

use strict;
use warnings;

my %bindings = ();
my $exitcode = 0;

while (<STDIN>) {
    my ($id, $xx, $role, $left, $arrow, $right) = split;
    if (defined $bindings{$left} && $bindings{$left} ne $right) {
        print "Conflict: $left bound to $bindings{$left} and $right\n";
        $exitcode = 1;
        }
    else {
        $bindings{$left} = $right;
        }
    }

exit $exitcode;