function practiceSessions(input) {
    let roads = {};
    for (let line of input) {
        if (line === 'END') {
            break;
        }
        line = line.split('->');
        let command = line[0];
        let roadName = line[1];
        let racer = line[2];

        if (command === 'Add') {
            if (!roads.hasOwnProperty(roadName)) {
                roads[roadName] = [racer];
            } else {
                roads[roadName].push(racer);
            }
        } else if (command === 'Move') {

            let nextRoad = line[3];
            if (roads.hasOwnProperty(roadName)) {
                let indexOfRacer = roads[roadName].indexOf(racer);
                let racerName = roads[roadName][indexOfRacer];
                if (indexOfRacer !== -1) {
                    roads[roadName].splice(indexOfRacer, 1);
                    roads[nextRoad].push(racerName);
                }
            }
        } else if (command === 'Close') {
            if (roads.hasOwnProperty(roadName)) {
                delete (roads[roadName]);
            }
        }
    }
    let sortedRoads = Object.entries(roads)
        .sort((a, b) => b[1].length - a[1].length || a[0].localeCompare(b[0]));
    console.log('Practice sessions:');
    for (let [road, racers] of sortedRoads) {
        console.log(road);
        racers.forEach(racer => {
            console.log(`++${racer}`)
        });
    }
}