scratchpad newbie1991 <code> print "Enter the file containing the amino acid sequence \n"; my $filename = <STDIN>; chomp $filename; unless (open(FILENAME, $filename)) { print "File $filename not found. Exiting program \n"; exit; } my @AASeq=<FILENAME>; close FILENAME; my $AASeq = join('', @AASeq); $AASeq =~ s/\s//g; my $length = length $AASeq; </code>