#!/usr/bin/perl
#use strict;
open(FILE1,"C:/Perl/BX/BX-Users.csv");
open(FILE2,"C:/Perl/BX/BX-Books.csv");
open(FILE3,"C:/Perl/BX/BX-Book-Ratings.csv");
 
open(result1,">C:/Perl/BX/BX-Users.txt");
my %table;
my $record1;
my $count1;
#my $i=0;
<FILE1>;
while($_=<FILE1>)
{
    if($_ =~ /NULL$/){
         
     
        next
 
 
    }
    else{
    s/"//g;
    my @list=split /;/,$_;
    #print"@list";
    push @{$table{$list[0]}},$list[2];
    #print "$record1";
    #$i++;
    }
     
     
}
foreach my $userId(sort keys %table)
{
    my @AGE=@{$table{$userId}};
    syswrite(result1,"$userId,@AGE");
    $count1++;
}
print "$count1";
close(FILE1);
close(result1);
 
close(FILE2);
close(FILE3);