str = gets.chomp.downcase.gsub(" ","")
alfa = [*'a'..'z']
c = Array.new(26) { 0 }

str.chars.each do |v|
  alfa.each_with_index do |a,i|
    c[i] += 1 if a == v
  end
end

alfa.each_with_index do |a,i|
  puts "#{a} : #{c[i]}"
end