switch ([MM]) {
case    'I': return 1.0;
case   'II': return 2.0;
case  'III': return 3.0;
case   'IV': return 4.0;
case    'V': return 5.0;
case   'VI': return 6.0;
case  'VII': return 7.0;
case 'VIII': return 8.0;
case   'IX': return 9.0;
case    'X': return 10.0;
case   'XI': return 11.0;
case  'XII': return 12.0;
}