#!/usr/bin/perl -w

use bignum;

#bug: when rounding e.g. 9.9999999 to 10.000 no attempt is made to
#     accomodate the extra digit

while(<>){
	s{(?<![^ ])( *)(?<![\d\.])(-?(?:\d+|\d\d?\d?(?:,\d\d\d)+))(?![\dKMGT,])}{
		$s=$1;
		$n=$2;
		$w=length($n)+length($s);
		$comma=($n=~s/,//g);
		$neg=($n=~s/^-//);
		if($n>=1024*1024*1024*1024){
			$t="T";
			$n/=1024*1024*1024*1024;
		}elsif($n>=1024*1024*1024){
			$t="G";
			$n/=1024*1024*1024;
		}elsif($n>=1024*1024){
			$t="M";
			$n/=1024*1024;
		}elsif($n>=1024){
			$t="k";
			$n/=1024;
		}else{
			$t="";
		}
		if($comma&&length($n)>4){
			$n=~s/(\..*)$//;
			$end=$1;
			$n=~s/(?<=.)(?=(?:...)+)$/,/g;
			$n.=$end;
		}
		$pad=$w-length($n)-length($t)-$neg;
		if($pad<0){
			$pad=-$pad;
			if($n=~s/^(.*?)\.(\d*)(.{$pad})$/$1$2/){
				($a,$b)=($1,$2);
				if(substr($3,0,1)>=5){
					++$b;
					if(length($b)>length($2)){
						++$a;
						$b=substr($b,1);
					}
				}
				$n="$a".".$b";
			}
		}elsif($pad>0){
			$n=(' 'x$pad).$n;
		}
		$n="-$n" if $neg;
		$n.=$t;
		$n
	}egi;
	print;
}