How do you find the key of a value in hash in Perl?

%FM = (
              'Radio City' => '91.1',
              'Big FM' => '92.7',
              'Red FM' => '93.5',
              'Radio One' => '94.3',
              'Radio Mirchi' => '98.3',
              'Fever' => '104.0',
              'Oye FM' => '104.8',
              'FM Rainbow' => '107.1',
              'FM Gold' => '100.7',
             );

my ($key) = grep{ $FM{$_} eq '92.7' } keys %FM;
print $key;