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

my @str = ('{{1,1},2,{1,1}}',                       # the function should return 10
           '{1,{4,{6}}}',                           # the function should return 27
           '{{1,1,1,1},{1,1,{2,2}},{1,{2,{3,3}}}}', # Buk 56
           '{1,{{13}}}'                             # mine.. two digit tests 40
);

my $w = 0;  # weight or depth
print  "$_\t=>\t".(
                     eval join ('',
                      map{ /{/  ? ++$w && '(' :
                           /\d/ ? $w.'*'.$_   :
                           /,/  ? '+'         :
                           /}/  ? $w-- && ')' :
                           $_
                      }($_=~/\d+|./g)
                     )
                    )."\n" for @str;

#OUTPUT

{{1,1},2,{1,1}} =>      10
{1,{4,{6}}}     =>      27
{{1,1,1,1},{1,1,{2,2}},{1,{2,{3,3}}}}   =>      56
{1,{{13}}}      =>      40