#!/usr/bin/perl

use strict;
use Regexp::Common;

die "Usage: $0 multiplier_number [input.file]\n"
    unless ( @ARGV and $ARGV[0] =~ /^$RE{num}{real}$/ );

my $df = shift;  # take the numeric arg off @ARGV

while (<>)   # read from STDIN, or from file(s) named in @ARGV
{
    if ( ! /^\s*(?:$RE{num}{real}\s+)+$/ ) {   # if line has non-numerics
        print;
    }
    else {
        my @vals = map { $_ * $df * 50 } split;
        print join( "\t", @vals ), "\n";
    }
}