#!perl -slw
use strict;

my ($chromosomes,$DELIMITER) = (undef,'CLUSTER');
while ( <DATA> ) {
    s/\R//g; # remove line breaks;
    my $record = [split /\s+/];
    push @{$chromosomes->{$record->[0]}->{$record->[2]}},[$record->[1],$record->[3]];
}

foreach my $chrM (sort keys %{$chromosomes}) {
    my $cnt = 0; # used to print delimiter

    foreach my $UMI (sort {$a cmp $b} keys %{$chromosomes->{$chrM}}) {
	print $DELIMITER unless $cnt++ % 3;
	print "$chrM\t$_->[0]\t$UMI\t$_->[1]" 
	    foreach (sort {$a->[0] <=> $b->[0] or
			       $a->[1] <=> $b->[1]} @{$chromosomes->{$chrM}->{$UMI}});

    }
}
__DATA__
chrM:307    0    AGCGGGGA    129
chrM:307    0    AGCGGGGA    130
chrM:307    0    AGCGGGGA    129
chrM:308    0    AGCGGGGA    129
chrM:308    0    AGCGGGGA    130
chrM:308    0    AGCGGGGA    129
chrM:309    0    AGCGGGGA    129
chrM:309    0    AGCGGGGA    130
chrM:309    0    AGCGGGGA    129
chrM:307    0    TCAAAATG    130
chrM:308    0    TCAAAATG    130
chrM:309    0    TCAAAATG    130
chrM:307    0    TCACGGTG    130
chrM:308    0    TCACGGTG    130
chrM:309    0    TCACGGTG    130
chrM:307    0    TCAGCCTG    129
chrM:308    0    TCAGCCTG    129
chrM:309    0    TCAGCCTG    129
chrM:307    0    TCAGGGAG    130
chrM:308    0    TCAGGGAG    130
chrM:309    0    TCAGGGAG    130
chrM:307    1    TCAGGGTG    106
chrM:307    2    TCAGGGTG    130
chrM:307    2    TCAGGGTG    129
chrM:308    1    TCAGGGTG    106
chrM:308    2    TCAGGGTG    130
chrM:308    2    TCAGGGTG    129
chrM:309    1    TCAGGGTG    106
chrM:309    2    TCAGGGTG    130
chrM:309    2    TCAGGGTG    129