Math bot

print("Hi, I'm Marvin, your personal assistant.")
your_name = input("What's your name?\n")
print("Welcome " + your_name + "!")
opr = input("How may I assist you with?\n")
if opr == "add" or opr == "Add":
    num1 = input("Enter first number.\n")
    num2 = input("Enter second number.\n")
    result = int(num1) + int(num2)
    output = str(result)
    print(num1 + "+" + num2 + "=" + output)
elif opr == "substract" or opr == "Substract":
    num1 = input("Enter first number.\n")
    num2 = input("Enter second number.\n")
    result = int(num1) - int(num2)
    output = str(result)
    print(num1 + "-" + num2 + "=" + output)
elif opr == "multiply" or opr == "Multiply":
    num1 = input("Enter first number.\n")
    num2 = input("Enter second number.\n")
    result = int(num1) * int(num2)
    output = str(result)
    print(num1 + "*" + num2 + "=" + output)
elif opr == "divide" or opr == "Divide":
    num1 = input("Enter first number.\n")
    num2 = input("Enter second number.\n")
    result = int(num1) / int(num2)
    output = str(result)
    print(num1 + "/" + num2 + "=" + output)
else:
    print("I'm not capable of doing " + opr + " at the moment. You should keep upgrading me.")