function exam(input) {
    let examHour = +(input.shift());
    let examMinutes = +(input.shift());
    let arriveHour = +(input.shift());
    let arriveMinutes = +(input.shift());
    let examTotalMinutes = examHour * 60 + examMinutes;
    let arriveTotoalMinutes = arriveHour * 60 + arriveMinutes;
    let difference = examTotalMinutes - arriveTotoalMinutes;

    if (difference >= 0 && difference <= 30) {
        console.log("On time");
        console.log(`${difference} minutes before the start`);
    } else if (difference > 30 && difference <= 59) {
        console.log("Early");
        console.log(`${difference} minutes before the start`);
    } else if (difference > 30 && difference >= 60) {
        console.log("Early");
        let hour = Math.trunc(difference / 60);
        let min = difference % 60;
        if (min < 9) {
            console.log(`${hour} 0${min} hours before the start`);
        } else {
            console.log(`${hour} ${min} hours before the start`);
        }
    } else if (difference < 0 && difference >= -59) {
        console.log("Late");
        let min = Math.abs(difference);
        console.log(`${Math.abs(difference)} minutes after the start`);
    } else if (difference < -60) {
        console.log("Late");
        let hour = Math.trunc(difference / 60);
        let min = Math.abs(difference % 60);
        if (min < 9) {
            console.log(`${Math.abs(hour)} 0${min} hours after the start`);
        } else {
            console.log(`${Math.abs(hour)} ${min} hours after the start`);
        }

    }
}