diff --git a/4.1_Random_Password.py b/4.1_Random_Password.py
new file mode 100644
index 0000000..d79e640
--- /dev/null
+++ b/4.1_Random_Password.py
@@ -0,0 +1,67 @@
+'''
+As a user, I want to use a program which can generate random password and display the result on user interface. So that I can generate my password for any application.
+
+Acceptance Criteria:
+
+Password length must be 10 characters long.
+It must contain at least 2 upper case letter, 2 digits and 2 special symbols.
+You must import some required modules or packages.
+The GUI of program must contain at least a button and a label.
+The result should be display on the password label when the user click the generate button.
+'''
+
+
+# http://54.234.188.223:8501/
+# streamlit run app.py
+
+from random import choice,shuffle
+import streamlit as st
+html_temp = """
+<div style="width:700px;background-color:black;padding:10px">
+<h1 style="color:white;text-align:center;">Generate Your Password</h1>
+</div>"""
+st.markdown(html_temp,unsafe_allow_html=True)
+
+from PIL import Image
+im = Image.open("image.jpg")
+st.image(im, width=700)
+
+upper_cases='ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+lower_cases='abcdefghijklmnopqrstuvwxyz'
+digits='0123456789'
+specials='!"#$%&\()*+,-./:;<=>?@[]^_`{|}~'
+all_char=upper_cases+lower_cases+digits+specials
+
+st.sidebar.header("Configure the Password Features:")
+lenght=st.slider('What is the lenght of password?',0,20,10)
+upper_case_count=st.sidebar.slider('What is the count of the upper cases at least?',0,10,2)
+lower_case_count=st.sidebar.slider('What is the count of the lower cases at least?',0,10,2)  
+digit_count=st.sidebar.slider('What is the count of the digits at least?',0,10,2)  
+special_count=st.sidebar.slider('What is the count of the special characters at least?',0,10,2)
+
+
+if st.button('Generate'):
+    upper,lower,special,digit,password=['' for _ in range(5)]
+
+    for i in range(upper_case_count):
+        upper += choice(upper_cases)
+
+    for i in range(lower_case_count):
+        lower += choice(lower_cases)
+
+    for i in range(digit_count):
+        digit += choice(digits)
+
+    for i in range(special_count):
+        special += choice(specials)
+
+    must_be = upper + lower + digit + special
+
+    for i in range(lenght-len(must_be)):
+        password += choice(all_char)
+
+    password+=must_be
+    password=list(password)
+    shuffle(password)
+
+    st.success(f'''Password: "{''.join(password)}"''')
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diff --git a/4.2_The_Least_Common_Multiple.py b/4.2_The_Least_Common_Multiple.py
new file mode 100644
index 0000000..1e83fdd
--- /dev/null
+++ b/4.2_The_Least_Common_Multiple.py
@@ -0,0 +1,35 @@
+"""
+2 - The Least Common Multiple
+
+As a user, I want to use a program which can calculate the least common multiple (L.C.M.) of four numbers. So that I can find the least common multiple (L.C.M.) of my inputs.
+
+Acceptance Criteria:
+
+Ask user to enter the four numbers.
+Use try/except blocks to verify input entries and warn the user for Nan or non numerical inputs.
+Calculate the least common multiple (L.C.M.) of four numbers
+Use gcd function in module of math
+"""
+from math import gcd
+
+def isValid(n:str) ->bool:
+    try:
+        1/int(n)
+    except Exception:
+        print("Entry is invalid! Try again...\n")
+        return False
+    else:
+        return True
+
+nums=[]
+while len(nums)<4:
+    n=input(f"Number_{len(nums)+1}: ")
+    if isValid(n): nums.append(int(n))
+        
+gcd1 = gcd(nums[0],nums[1])
+gcd2 = gcd(nums[2],nums[3])
+lcm_1 = nums[0]*nums[1] // gcd1
+lcm_2 = nums[2]*nums[3] // gcd2
+
+print(f"\nEBOB{nums} = {gcd(gcd1,gcd2)}\n"
+      f"EKOK{nums} = {lcm_1*lcm_2//gcd(lcm_1,lcm_2)}")
\ No newline at end of file
diff --git a/4.3_Number_Guessing_Game.py b/4.3_Number_Guessing_Game.py
new file mode 100644
index 0000000..b05227e
--- /dev/null
+++ b/4.3_Number_Guessing_Game.py
@@ -0,0 +1,35 @@
+'''
+3- Number Guessing Game
+
+As a player, I want to play a game which I can guess a number the computer chooses in the range I chose. So that I can try to find the correct number which was selected by computer.
+Acceptance Criteria:
+
+Computer must randomly pick an integer from user selected a range, i.e., from A to B, where A and B belong to Integer.
+Your program should prompt the user for guesses
+if the user guesses incorrectly, it should print whether the guess is too high or too low.
+If the user guesses correctly, the program should print total time and total number of guesses.
+You must import some required modules or packages
+You can assume that the user will enter valid input.
+'''
+
+from random import randint
+from time import time
+
+target=randint(int(input('Lower Limit: ')),int(input('Upper Limit: ')))
+
+print('Predict the Number:')
+diff=time()
+counter=0
+while True:
+    p=int(input())
+    counter+=1
+    if p==target:
+        diff=time()-diff
+        print(f'\nCongratulations!!!\nTarget Number is {target}',
+              f'Number of Guesses: {counter}',
+              f'Time Passed: {round(diff,1)} sec.',sep='\n')
+        break
+    else:
+        if p > target: print('Too low...')
+        else: print('Too high...')
+        
\ No newline at end of file
diff --git a/4.4_Mis_Calculator.py b/4.4_Mis_Calculator.py
new file mode 100644
index 0000000..57131b5
--- /dev/null
+++ b/4.4_Mis_Calculator.py
@@ -0,0 +1,51 @@
+"""
+4- Mis Calculator
+
+As a user, I want to use a program which can calculate basic mathematical operations. So that I can add, subtract, multiply or divide my inputs.
+Acceptance Criteria:
+
+The calculator must support the Addition, Subtraction, Multiplication and Division operations.
+Define four functions in four files for each of them, with two float numbers as parameters.
+To calculate the answer, use math.ceil() and get the next integer value greater than the result
+Create a menu using the print command with the respective options and take an input choice from the user.
+Using if/elif statements for cases and call the appropriate functions.
+Use try/except blocks to verify input entries and warn the user for incorrect inputs.
+Ask user if calculate numbers again. To implement this, take the input from user Y or N.
+"""
+
+import math
+from operations import add, sum, multiply, divide
+
+def isValid(n:str) ->bool:
+    try:
+        float(n)
+    except Exception:
+        print("Entry is invalid! Try again...\n")
+        return False
+    else:
+        return True
+while True:
+    nums=[]
+    while len(nums)<2:
+        n=input(f"Number_{len(nums)+1}: ")
+        if isValid(n): nums.append(int(n))
+
+    while True:
+        op=int(input('1-Addition\n2-Subtraction\n3-Multiplication\n4-Division\n\nSelect the operation number from the list above: '))
+        if op in [1,2,3,4]: break
+        print("Entry is invalid! Try again...\n")
+
+    if op==1:
+        result=add(nums[0],nums[1])
+    elif op==2:
+        result=sum(nums[0],nums[1])
+    elif op==3:
+        result=multiply(nums[0],nums[1])
+    elif op==4 and nums[1] != 0:
+        result=divide(nums[0],nums[1])
+
+    operate = (op==1)*'+' or (op==2)*'-' or (op==3)*'*' or (op==4)*'/'
+    print(f"{nums[0]} {operate} {nums[1]} = {math.ceil(result)}")
+    
+    if input('Do you want to continue? [y/n]:').lower()=='n':
+        break
\ No newline at end of file
diff --git a/image.jpg b/image.jpg
new file mode 100644
index 0000000..2123316
Binary files /dev/null and b/image.jpg differ
diff --git a/operations.py b/operations.py
new file mode 100644
index 0000000..5c56c39
--- /dev/null
+++ b/operations.py
@@ -0,0 +1,11 @@
+def add(a,b):
+    return a+b
+
+def sum(a,b):
+    return a-b
+
+def multiply(a,b):
+    return a*b
+
+def divide(a,b):
+    return a/b
\ No newline at end of file