#!/usr/bin/perl

use strict;

my @lines = <>;

my $output = '';

while(@lines) {
  my $chords = shift @lines;
  if($chords =~ /^\s*$/) {
    $output .= "\n";
    next;
  }
  my $lyrics = shift @lines;
  my $chord_offset = 0;
  my $lyric_offset = 0;
  while($chords) {
    print STDERR "Chord offset: $chord_offset\tLyric offse: $lyric_offset\n";
    print STDERR "Chords: <$chords>\n";
    print STDERR "Lyrics: <$lyrics>\n";
    if($chords =~ s/^(\s+)//) {
      $chord_offset += length $1;
    }
    if($chords =~ s/^(\S+)//) {
      my $chord = $1;
      $chord_offset += length $chord;
      $chord = "[$chord]";
      substr($lyrics, $lyric_offset + $chord_offset, 0, $chord);
      $lyric_offset += length $chord;
    }
  }
  $output .= "$lyrics";
}

print $output;