function read(done) {
    require("fs").readFile('./input', 'utf8', (err, data) => {
        var taskPool = new TaskPool();
        data.split("\n").forEach((line) => {
            var arr = line.match(/\s([A-Z])\s.*\s([A-Z])\s/);
            if (arr) {
                var from = taskPool.getOrCreate(arr[1]),
                    to = taskPool.getOrCreate(arr[2]);
                from.neededBy.push(to);
                to.needs.push(from);
            }
        });
        done(taskPool);
    });
}

function Task(taskId) {
    this.taskId = taskId;
    this.done = false;
    this.startedAt = -1;
    this.duration = 61 +taskId.charCodeAt(0) -"A".charCodeAt(0);
    this.needs = [];
    this.neededBy = [];
}

Task.prototype.isReady = function() {
    var c = true;
    this.needs.some(i => {
        c &= i.done;
        return !c;
    });
    return c;
}

function TaskPool() {
    this.tasks = {},
    this.getOrCreate = function(taskId) {
        if (this.tasks[taskId])
            return this.tasks[taskId];
        return this.tasks[taskId] = new Task(taskId);
    };
}

Array.prototype.containsAll = function(arr) {
    var all = true;
    arr.some(i => {
        if (this.indexOf(i.taskId) == -1)
            all = false;
        return !all;
    });
    return all;
}

function nextObj(taskPool) {
    var canDo = [];
    for (var i in taskPool.tasks) {
        var t = taskPool.tasks[i];
        if (!t.done && t.startedAt < 0 && t.isReady())
            canDo.push(i);
    }
    canDo.sort();
    if (canDo.length)
        taskPool.tasks[canDo[0]].done = 1;
    return taskPool.tasks[canDo[0]];
}

function nextObjTime(taskPool, currentTime, nbWorkers) {
    var remainTask = 0,
        taskToFinish = 0;
    for (var i in taskPool.tasks) {
        var t = taskPool.tasks[i];
        if (!t.done && t.startedAt >= 0) {
            if (t.startedAt +t.duration <= currentTime)
                t.done = true;
            else
                --nbWorkers;
        }
        if (t.startedAt == -1)
            ++remainTask;
        if (!t.done)
            ++taskToFinish;
    }
    while (nbWorkers > 0 && remainTask) {
        var task = nextObj(taskPool);
        if (task) {
            task.done = false;
            task.startedAt = currentTime;
            --remainTask;
        }
        else
            return true;
        --nbWorkers;
    }
    return taskToFinish > 0;
}

function ex1() {
    read(function(taskPool){
        var result = "";
        while (true) {
            var step = nextObj(taskPool);
            if (!step)
                break;
            result += step.taskId;
        }
        console.log(result);
    });
}

function ex2() {
    read(function(taskPool){
        var time =0;
        while (true) {
            var step = nextObjTime(taskPool, time, 5);
            if (!step)
                break;
            ++time;
        }
        console.log(time);
    });
}

ex1();
ex2();