Ruby Beginner - Spacing issue : I am new to ruby and I am practicing conversions with numbers and strings. I have an issue with the spacing for the following code below:

puts 'Hello, what\'s your first name?'
firstName = gets.chomp
puts 'What is your middle name?'
middleName = gets.chomp
puts 'Finally, what is your last name?'
lastName = gets.chomp
puts 'Nice to meet you ' + firstName + middleName + lastName + '. :)'

The last part does not space out once it has been run on Terminal. 

Please help, Thanks :)