# 5! = 5 * 4 * 3 * 2 *1 = 120
# 5! = 120

puts "I'll compute factorial. What is your number?"
number = gets.chomp.to_i

factorial = 1
countdown = number

countdown.times do
  puts " * " + countdown.to_s
  factorial *= countdown
  countdown -= 1
end

puts number.to_s + "! is: " + factorial.to_s




# factorial *= countdown
# factorial = factorial * countdown
# 
# 
# countdown -= 1
# countdown = countdown - 1