diff --git a/Exercise_1.py b/Exercise_1.py
index 532833f5d..6ecfe9fa0 100644
--- a/Exercise_1.py
+++ b/Exercise_1.py
@@ -1,24 +1,50 @@
+
+#Time Complexity :
+#Space Complexity :
+#Did this code successfully run on Leetcode :
+#Any problem you faced while coding this :
+
+#Your code here along with comments explaining your approach
+
+#Exercise_1 : Implement Stack using Array.
 class myStack:
-  #Please read sample.java file before starting.
-  #Kindly include Time and Space complexity at top of each file
-     def __init__(self):
+      #initializing the stack and top variable
+     def __init__(self): 
+      self.stack = []
+      self.top = -1
          
      def isEmpty(self):
-         
+      return self.top == -1
+    
      def push(self, item):
+      self.top += 1
+      self.stack.append(item)
          
      def pop(self):
-        
+      if self.top == -1:
+        print("stack is empty")
+        return None
+      self.top -= 1
+      return self.stack.pop()
         
      def peek(self):
-        
+      return self.stack[self.top]
+     
      def size(self):
-         
+      count = 0
+      for i in range(self.top, -1, -1):
+        if self.top == -1:
+          count = 0
+        else:
+          count += 1
+      return count
+
      def show(self):
-         
+      for i in range(self.top, -1, -1):
+        print(self.stack[i])
 
 s = myStack()
 s.push('1')
 s.push('2')
-print(s.pop())
-print(s.show())
+s.pop()
+s.show()