def add(x, y):  

   """This function adds two numbers"" 

   return x + y 

def subtract(x, y): 

   """This function subtracts two numbers""" 

   return x - y 

def multiply(x, y): 

   """This function multiplies two numbers""" 

   return x * y 

def divide(x, y): 

   """This function divides two numbers"""  

   return x / y  

  

print("Select operation.")  

print("1.Add")  

print("2.Subtract")  

print("3.Multiply")  

print("4.Divide")  

  

choice = input("Enter choice(1/2/3/4):")  

  

num1 = int(input("Enter first number: "))  

num2 = int(input("Enter second number: "))  

  

if choice == '1':  

   print(num1,"+",num2,"=", add(num1,num2))  

  

elif choice == '2':  

   print(num1,"-",num2,"=", subtract(num1,num2))  

  

elif choice == '3':  

   print(num1,"*",num2,"=", multiply(num1,num2))  

elif choice == '4':  

   print(num1,"/",num2,"=", divide(num1,num2))  

else:  

   print("Invalid input")
