let hours = s.split(':')[0].toString();
let minutes = s.split(':')[1].toString();
let seconds = (s.split(':')[2].slice(0, 2)).toString();
let timeType = s.split(':')[2].slice(-2);

if (timeType == 'AM' && hours == '12') {
   hours = '00';
} else if (timeType == 'PM' && Number(hours) < 12) {
   hours = (Number(hours) + 12).toString();
}

return `${hours}:${minutes}:${seconds}`;