diff --git a/Environment.py b/Environment.py
index c205ca6..b05ce0b 100644
--- a/Environment.py
+++ b/Environment.py
@@ -83,7 +83,7 @@ class Env:
     '''
         Get shortest calcualted path and print it
     '''
-    def print_shortest_path(self, Q):
+    def print_shortest_path(self, Q: dict): -> None
         path = [self.start]
         state = self.start
         while state!=self.goal:
@@ -101,7 +101,7 @@ class Env:
     '''
         Plot graph
     '''
-    def plot_graph(self, path):
+    def plot_graph(self, path: list): -> None
         node_color = []
         edge_color = []
         edge_width = []