#!/usr/pkg/bin/perl
$r=$ARGV[0];
$s=$ARGV[1];
$m=0;
$count=$ARGV[2]?$ARGV[2]:1;
for(;$l=<stdin> and $count > 0;) {
 if($m == 0) {
  if($l =~ $r) {
   $m=1;
   print $l;
   next;
 }}
 if($m == 1) {
  print $l;
  if($l =~ $s) {
   $m=0;
   $count--;
}}}