use strict;
use warnings;

my $lastrow = "";
while (my $line = <DATA>) {
	$line =~ /(.*?)\n/;
	$line = $1;
	if ($line ne $lastrow) {
		print $line, "\n";
		$lastrow = $line;
	}
}
__DATA__
data_row_051126120432.data 
data_row_051126120630.data 
data_row_051126120630.data 
data_row_051126122305.data 
data_row_051126122305.data