#!/usr/bin/env perl
use strict;
use warnings FATAL => 'all';

my $version = shift or die "no version specified!";
my $changelog = shift or die "no changelog file specified!";

open my $fh, '<', $changelog
  or die "can't open $changelog: $!";
my $context;
my $found_version;
while (my $line = <$fh>) {
  if ($found_version) {
    last
      if $line =~ /^\S/;
    $context++;
  }
  elsif ($line =~ /^v?\Q$version\E/) {
    $found_version = 1;
  }
}
close $fh;
die "couldn't find heading for $version!"
  unless $found_version;

print "$context\n";