print('Lesson ','1','"start"...\n')

print("-------Demo 1-------\n")
str = input('Please input your name:\n')
print('Your input name is:',str)



print("-------Demo 2-------\n")
# Store input numbers
num1 = input('Enter first number: ')
num2 = input('Enter second number: ')
# Add two numbers
sum = float(num1) + float(num2)
# Display the sum
print('The sum of {0} and {1} is {2}'.format(num1, num2, sum))



print("-------Demo 3-------\n")
print('The sum is %.1f' %(float(input('Enter first number: ')) + float(input('Enter second number: '))))