How can I count characters in Perl?

I have the following Perl script counting the number of Fs and Ts in a string:

my $str = "GGGFFEEIIEETTGGG";
my $ft_count = 0;
$ft_count++ while($str =~ m/[FT]/g);
print "$ft_count\n";

Is there a more concise way to get the count (in other words, to combine line 2 and 3)?