prime_number

def mid_point(x,y)
	(x+y)/2.0
end
def square_root(x,e)
	if x == 1
		guess = 1
	else
		lowest = 0
		highest = x
		guess = mid_point(lowest,highest)
		range = (guess*guess)- x
		until range <= e and range > 0  do
			if range < 0
				lowest = guess
			else highest = guess
		end
			guess = mid_point(lowest, highest)
			range = (guess*guess)- x 
		end
		guess
	end
end

def prime_number?(x)
  sqrt = square_root(x, 0.00001)
  startvalue = 2
  endvalue = sqrt
  is_a_prime = true
  while startvalue <= endvalue
    if(x % startvalue == 0) 
      is_a_prime = false
    end
    startvalue = startvalue + 1
  end
  is_a_prime
end

print "Enter No.:"
x = Float $stdin.gets.chomp
prime_number?(x) ? puts("true") :  puts("false")