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

@ARGV = qw/ file1 file2/;

my %h;

while ( <> ) {
    /(\S+)\s+(\S+)/;
    $h{$1} = $h{$1} ? $h{$1}*$2 : $2;
}

print "$_ $h{$_}\n" for sort { $h{$a} <=> $h{$b} } keys %h;