diff --git a/bank.py b/bank.py
new file mode 100644
index 0000000..22add88
--- /dev/null
+++ b/bank.py
@@ -0,0 +1,24 @@
+from client import Client
+
+class Bank(Client):
+    clients=[]  # clients will be stored as its unique path in memory, not as name
+    
+    def __init__(self, name):
+        self.name=name 
+        
+        
+        
+    @classmethod
+    def add_client(cls,client):
+        cls.client=client
+        cls.clients.append(client)
+        
+    
+    def authentication(self,name,acc_No): #account number key to verify its name from database dict in CLient class
+        try :
+            if Client.data_base[acc_No]["name"] == name :  
+                return True    
+        except KeyError : 
+            print("Authentication failed! \nReason: Account not found.")
+
+
diff --git a/client.py b/client.py
new file mode 100644
index 0000000..4f86885
--- /dev/null
+++ b/client.py
@@ -0,0 +1,32 @@
+import random
+
+class Client():
+    data_base={}      #We keep clients as 'no : name,amount'
+    def __init__(self,name,total_amount):
+        self.name=name
+        self.total_amount=total_amount
+        self.acc_No=(''.join(random.sample('0123456789', 5)))#we assign 5 digits number as str
+        print("Account created successfully! Your account number is: %s "%(self.acc_No))
+        Client.data_base[self.acc_No]={"name" : self.name ,"total_amount" : self.total_amount}
+    def updated_amount(self):    #We need to save in dictionary current amount after transactions
+        Client.data_base.update({self.acc_No : {"total_amount" : self.total_amount}})
+        print("Transaction done.Now,you have  : %s"% (self.total_amount))
+
+    
+    def withdraw(self,amount):
+            self.total_amount -= amount
+            if amount>self.total_amount:
+              raise "insufficient balance"
+            else:
+                self.updated_amount() 
+   
+    def deposit(self,amount):
+        self.total_amount+=amount
+        print("%s has been added your account."%(amount))
+        self.updated_amount()
+
+
+    def balance(self):
+        s='Name :%s , Account Number : %s ,Current Balance : %d '%(self.name,self.acc_No,self.total_amount)
+        print(s)
+
diff --git a/main.py b/main.py
new file mode 100644
index 0000000..7e81ef2
--- /dev/null
+++ b/main.py
@@ -0,0 +1,54 @@
+from client import Client
+from bank import Bank
+
+
+
+int_bank=Bank("International")
+while True:  
+      option =input("""Welcome to International Bank
+    Choose an option:
+    1. Open new bank account
+    2. Open existing bank account
+    3. Exit \n Enter :""")
+      if option == "1":
+          name=input("Name :")
+          total_amount=int(input("Amount :"))
+          client=Client(name,total_amount)
+          int_bank.add_client(client)
+          print ("Acoount of %s,%s has been added"%(name,total_amount))
+          
+      elif option=="2":
+          print("To access your account, please enter your credentials below.")
+          acc_No=input("Account No : ")
+          name=input("Name : ")
+          if int_bank.authentication(name,acc_No):
+            
+           while True:
+                choice=input( """
+Welcome %s !
+Choose an option:
+  1. Withdraw
+  2. Deposit
+  3. Balance
+  4. Exit 
+"""%(name))
+                if choice=="1":
+                    amount=int(input("Withdraw Amount : "))
+                    for i in Bank.clients:
+                       i.withdraw(amount)
+                elif choice=="2":
+                    amount=int(input("Deposit Amount : "))
+                    for i in Bank.clients:
+                       i.deposit(amount)
+                    
+                elif choice=="3":
+                  for i in Bank.clients:
+                       i.balance()
+                elif choice=="4":
+                     break
+               
+      elif (option=="3"):
+        print("See you soon...")
+        break
+
+