#!/usr/bin/perl
use strict;
use warnings;

print " Enter the dilution factor. \n";
chomp (my $df = <STDIN>);
open FILE, "45well.txt" or die $!;
while (<FILE>){
    chomp;
    my @values = split ' ';
    foreach my $val (@values){
        my $DNA_conc = $val * $df * 50 ;
        print "$DNA_conc\n";
    }
}
close (FILE);