open(FILE1, "<", table.txt)

open(FILE2, "<", values.txt)

my %ids2proteins=();

   while(my $row = <FILE2>){
   chomp $row;
   
   my @column = split(/\t/, $row);
   my $protein_number = $column[0];
      
      while(my $line= <FILE1>){
      chomp $line;
      
      my @fields = split(/\t/, $line);
      my ($ids,$proteins) = ($fields[0],$fields[1]);
      $ids2proteins{$ids} = $proteins;
      
      foreach my $keys(keys %ids2proteins){
         my $values = $ids2proteins{$keys};
         
         if($values eq $protein_number){
            print "$keys => $protein_number";
}}}}