puts 'This program checks if a number is a prime number.'

a = 'y'

while a == 'y'

  puts 'Which number do you want to check?'
  number = gets.chomp.to_i
  time1 = Time.new
  if number == 2
    puts number.to_s + 'is a prime number'
  
  elsif number % 2 == 1 && number > 1
    m = 1
    rest = 1
    
    while rest > 0 && m < Math.sqrt(number).floor
      m = m + 2
      rest = number % m
    end
    
    if rest != 0
      puts number.to_s + ' is a prime number.'
    
    else
      puts number.to_s + ' is not a prime number.'
    end
  
  else
    puts number.to_s + ' is not a prime number.'
  end
  time2 = Time.new
  puts time1
  puts time2
  puts 'Do you want to check another number? (y or n)'
  a = gets.chomp.to_s
end
gets