diff --git a/src/main.py b/src/main.py
index 9a73136..a70096c 100644
--- a/src/main.py
+++ b/src/main.py
@@ -1,35 +1,14 @@
 #!/bin/python3
-from queue import Queue
+import random as rd
+from heapq import heappush, heappop
 
-class NoServerFreeError(Exception):
-    def __init__(self, message="No server free"):
-        self.message = message
-        super().__init__(self.message)
-
-class Request:
-    def __init__(self, lambda_val, current_time):
-        # exponential distribution, parameter λ
-        interval = random.expovariate(self.lambda_val)
-        new_time = self.current_time + interval
-
-        self.arrival_time = new_time
-        self.category = 1
-
-
-class Server_cluster:
-    def __init__(self, cluster_size, category, service_rate):
-        self.category = category
-        self.cluster_size = cluster_size
-        self.finish_time = [0.0]*cluster_size
-
-    def process_request(self, request, current_time):
-        free_servers = [i for i in range(self.cluster_size) if self.finish_time[i] <= current_time]
-        if not free_servers:
-            raise NoServerFreeError()
-        else:
-            interval = random.expovariate(self.service_rate)
-            finish = current_time + interval
-            self.finish_time[free_servers[0]] = finish
+class Event:
+    def __init__(self, event_type, additional_options):
+        self.event_type = event_type
+        if event_type == "request":
+            self.category = additional_options['category']
+        elif event_type == "router_finish":
+            self.request = additional_options['request']
 
 
 class Simulation:
@@ -45,7 +24,6 @@ class Simulation:
         # λ
         self.lambda_val = lambda_val
 
-        self.router_queue = Queue(maxsize = 100)
         self.router_state = 'idle'  # 'idle', 'processing', 'blocked'
 
         self.event_queue = Queue() # (arrival_time, category)
@@ -55,5 +33,28 @@ class Simulation:
         self.lost_requests = 0
         self.response_times = []
 
+    def next_request():
+        # exponential distribution, parameter λ
+        interval = random.expovariate(self.lambda_val)
+        new_time = self.current_time + interval
+        arrival_time = new_time
+
+        category = rd.randint(1, C) if C>1 else 1
+
+        request = Event("request", {"category": category})
+
+        heappush(self.event_queue, (arrival_time, request))
+
+    def router_process(request):
+        self.router_state = 'processing'
+        router_finish = Event("router_finish", {"request": request})
+        heappush(self.event_queue, (arrival_time, router_finish))
+
+    def process_request(self, request, current_time):
+        interval = random.expovariate(self.service_rate)
+        finish = current_time + interval
+
+
+