#!/usr/bin/perl -w
use strict;
while (my $str = <DATA>) {
    my $odd = $str =~ tr/1// & 1;
    print $str,"has an ",$odd?"odd":"even"," number of 1's",$/;
}
__DATA__
110101010110111010101
100000000000000000001
101010101010101010101
110000000000000000011
110100000000000000000
11