On Time For Exam

function onTimeExam(input) {
    let hourExam = Number(input[0]);
    let minutesExam = Number(input[1]);
    let arrivalHour = Number(input[2]);
    let arrivalMinutes = Number(input[3]);
    let totalExamMinutes = hourExam * 60 + minutesExam;
    let totalArrivalMinutes = arrivalHour * 60 + arrivalMinutes;
    let leftHours;
    let leftMins;
    let diff = Math.abs(totalExamMinutes - totalArrivalMinutes);

    if (totalArrivalMinutes > totalExamMinutes) {
        console.log("Late");
        if (diff >= 60) {
            leftHours = Math.floor(diff / 60);
            leftMins = diff % 60;
            if (leftMins < 10) {
                console.log(`${leftHours}:0${leftMins} hours after the start`);
            } else {
                console.log(`${leftHours}:${leftMins} hours after the start`);
            }
        } else {
            if (diff < 10) {
                console.log(`${diff} minutes after the start`);
            } else {
                console.log(`${diff} minutes after the start`);

            }
        }
    } else if (totalArrivalMinutes == totalExamMinutes) {
        console.log("On time");
    } else if (totalArrivalMinutes < totalExamMinutes) {
        if (diff <= 30) {
            console.log("On time");
            console.log(`${diff} minutes before the start`);
        } else {
            if (diff >= 60) {
                leftHours = Math.floor(diff / 60);
                leftMins = diff % 60;
                if (leftMins < 10) {
                    console.log("Early");
                    console.log(`${leftHours}:0${leftMins} hours before the start`);
                } else {
                    console.log("Early");
                    console.log(`${leftHours}:${leftMins} hours before the start`);
                }
            } else {
                console.log("Early");
                console.log(`${diff} minutes before the start`);
            }
        }
    }
}