use strict;
use warnings;

use File::Find::Rule qw( );
use File::Basename   qw( basename );

my %files;
for (
   File::Find::Rule
      ->file()
      ->name('*.rtf', '*.ftp')
      ->in('.')
) {
   my ($name, $ext) = basename($_) =~ /^(.*)\.(.*)\z/;
   ++$files{$name}{$ext};
}

for my $name (%files) {
   print("$name\n")
      if $files{$name}{rtf}
      && $files{$name}{ftp};
}