sally123,

Two things immediately jump out!

• You need to loop on reading your data.
• You need to initialize your variables before you loop.

Untested, this should get you started.

#!/usr/bin/perl -w

use strict;

open my $FH, "<", "./sample.txt";

my %count = ();

while ( my $genome = <$FH> )
{   ....

}
[download]

A good practice is to define the scope of your variables (my, local, our).

Good Luck