diff --git a/2018/day07.py b/2018/day07.py
new file mode 100644
index 0000000..1c32865
--- /dev/null
+++ b/2018/day07.py
@@ -0,0 +1,108 @@
+""" https://adventofcode.com/2018/day/5 """
+
+def readFile():
+    import os.path as p
+    dName = p.dirname(__file__)
+    fName = p.basename(__file__).split(".")[0]
+    
+    nodes = {}
+    with open(p.join(dName, "input", f"{fName}.txt"), "r") as f:
+        lines =  [(line[5:6], line[36:37]) for line in f.readlines()]
+    for l in lines:
+        if l[0] not in nodes:
+            nodes[l[0]] = Node(l[0])
+        if l[1] not in nodes:
+            nodes[l[1]] = Node(l[1])
+        nodes[l[0]].children.append(nodes[l[1]])
+        nodes[l[1]].parents.append(nodes[l[0]])
+    return nodes
+
+class Node:
+    def __init__(self, name):
+        self.name = name
+        self.parents = []
+        self.children = []
+        self.timeNeeded = ord(name) - 4
+
+class Worker:
+    def __init__(self):
+        self.working = False
+        self.node = None
+        self.time = 0
+
+    def work(self):
+        self.time -= 1
+        if self.time == 0:
+            self.working = False
+
+    def setNode(self, node):
+        self.node = node
+        self.working = True
+        self.time = self.node.timeNeeded
+
+def getStartNodes(vals):
+    l = []
+    for val in vals:
+        if len(vals[val].parents) == 0:
+            l.append(vals[val])
+    return l
+
+def selectNextNode(vals):
+    minVal, minIdx = None, -1
+    for i in range(len(vals)):
+        if minVal is None or ord(vals[i].name) < minVal:
+            minVal, minIdx = ord(vals[i].name), i
+    return vals[minIdx]
+        
+def part1(vals):
+    order = []
+    nodes = getStartNodes(vals)
+    while nodes:
+        n = selectNextNode(nodes)
+        nodes.remove(n)
+        order.append(n.name)
+        for child in n.children:
+            child.parents.remove(n)
+            if len(child.parents) == 0:
+                nodes.append(child)
+    return "".join(order)
+
+def stillWorking(worker):
+    for w in worker:
+        if w.working:
+            return True
+    return False
+
+def part2(vals, numOfWorker):
+    order = []
+    time = 0
+    nodes = getStartNodes(vals)
+    worker = [Worker() for i in range(numOfWorker)]
+    while nodes or stillWorking(worker):
+        temp = []
+        for w in worker:
+            if not w.working:
+                if len(nodes) == 0:
+                    continue
+                else:
+                    n = selectNextNode(nodes)
+                    w.setNode(n)
+                    nodes.remove(n)
+            if w.working:
+                w.work()
+                if not w.working:
+                    # finished working
+                    order.append(w.node.name)
+                    for child in w.node.children:
+                        child.parents.remove(w.node)
+                        if len(child.parents) == 0:
+                            temp.append(child)
+        nodes += temp
+        time += 1
+    return time
+
+if __name__ == "__main__":
+    vals = readFile()
+    print(f"Part 1: {part1(vals)}")
+    vals = readFile()
+    print(f"Part 2: {part2(vals, 5)}")
\ No newline at end of file
diff --git a/2018/input/day07.txt b/2018/input/day07.txt
new file mode 100644
index 0000000..8ab8024
--- /dev/null
+++ b/2018/input/day07.txt
@@ -0,0 +1,101 @@
+Step F must be finished before step Q can begin.
+Step A must be finished before step K can begin.
+Step K must be finished before step R can begin.
+Step D must be finished before step X can begin.
+Step L must be finished before step T can begin.
+Step V must be finished before step W can begin.
+Step J must be finished before step N can begin.
+Step B must be finished before step W can begin.
+Step X must be finished before step C can begin.
+Step W must be finished before step I can begin.
+Step Q must be finished before step P can begin.
+Step E must be finished before step M can begin.
+Step C must be finished before step N can begin.
+Step U must be finished before step O can begin.
+Step O must be finished before step R can begin.
+Step N must be finished before step Z can begin.
+Step R must be finished before step I can begin.
+Step G must be finished before step H can begin.
+Step T must be finished before step H can begin.
+Step M must be finished before step P can begin.
+Step Y must be finished before step I can begin.
+Step S must be finished before step Z can begin.
+Step I must be finished before step H can begin.
+Step H must be finished before step P can begin.
+Step P must be finished before step Z can begin.
+Step Y must be finished before step P can begin.
+Step A must be finished before step O can begin.
+Step V must be finished before step O can begin.
+Step G must be finished before step Y can begin.
+Step K must be finished before step B can begin.
+Step I must be finished before step P can begin.
+Step D must be finished before step L can begin.
+Step A must be finished before step P can begin.
+Step O must be finished before step T can begin.
+Step F must be finished before step C can begin.
+Step M must be finished before step S can begin.
+Step V must be finished before step Q can begin.
+Step G must be finished before step I can begin.
+Step O must be finished before step I can begin.
+Step N must be finished before step I can begin.
+Step E must be finished before step O can begin.
+Step N must be finished before step S can begin.
+Step J must be finished before step H can begin.
+Step C must be finished before step P can begin.
+Step E must be finished before step N can begin.
+Step T must be finished before step P can begin.
+Step A must be finished before step G can begin.
+Step A must be finished before step V can begin.
+Step C must be finished before step H can begin.
+Step A must be finished before step Y can begin.
+Step E must be finished before step U can begin.
+Step T must be finished before step Y can begin.
+Step Q must be finished before step S can begin.
+Step Y must be finished before step S can begin.
+Step E must be finished before step P can begin.
+Step N must be finished before step T can begin.
+Step T must be finished before step M can begin.
+Step Q must be finished before step M can begin.
+Step H must be finished before step Z can begin.
+Step D must be finished before step Y can begin.
+Step J must be finished before step R can begin.
+Step U must be finished before step R can begin.
+Step K must be finished before step N can begin.
+Step A must be finished before step W can begin.
+Step A must be finished before step H can begin.
+Step X must be finished before step G can begin.
+Step V must be finished before step J can begin.
+Step W must be finished before step C can begin.
+Step I must be finished before step Z can begin.
+Step V must be finished before step H can begin.
+Step R must be finished before step H can begin.
+Step U must be finished before step N can begin.
+Step O must be finished before step Z can begin.
+Step X must be finished before step S can begin.
+Step E must be finished before step G can begin.
+Step W must be finished before step U can begin.
+Step U must be finished before step G can begin.
+Step D must be finished before step Z can begin.
+Step E must be finished before step R can begin.
+Step L must be finished before step B can begin.
+Step B must be finished before step R can begin.
+Step G must be finished before step T can begin.
+Step F must be finished before step K can begin.
+Step R must be finished before step S can begin.
+Step J must be finished before step Z can begin.
+Step Q must be finished before step U can begin.
+Step X must be finished before step O can begin.
+Step F must be finished before step I can begin.
+Step W must be finished before step R can begin.
+Step W must be finished before step Y can begin.
+Step M must be finished before step Y can begin.
+Step S must be finished before step I can begin.
+Step F must be finished before step O can begin.
+Step C must be finished before step Y can begin.
+Step N must be finished before step G can begin.
+Step O must be finished before step S can begin.
+Step Q must be finished before step O can begin.
+Step K must be finished before step T can begin.
+Step X must be finished before step Z can begin.
+Step L must be finished before step N can begin.
+Step S must be finished before step P can begin.