#!/usr/bin/perl -w

use strict;
# ./acro WORD INPUT
# ./acro WORD < INPUT

my $re =
  join '[\s.,;!?\'"]+',
  map "(?<![\\w'])${_}[\\w']*",
  split //,
  shift;

{ local $/; ($_ = <>) =~ tr/\n\r\t\f / /s; }
while (/(?=(${re}[.,;!?'"]*))/iog) { print "$1\n" }