task.rb

total = 0
cur = 0
puts "Enter numbers separated by commas and press 'Enter'"
array = gets.chomp
puts "Enter X:"
X = gets.chomp
A = array.split(',')
n = A.length
A.each do |a|
	total+=1 if a == X
end
if total == 0 
	puts "-1"
elsif n != total 
	os = n
	for i in 0...n
		os-=1
		cur +=1 if A[i] == X
		if os - (total-cur)==cur 
			answer = i+1
			puts "Answer: #{answer}"
		end
	end
elsif n == total
	puts "All the same"
end