alphabet = {
    "a" => 0,
    "b" => 0,
    "c" => 0,
    "d" => 0,
    "e" => 0,
    "f" => 0,
    "g" => 0,
    "h" => 0,
    "i" => 0,
    "j" => 0,
    "k" => 0,
    "l" => 0,
    "m" => 0,
    "n" => 0,
    "o" => 0,
    "p" => 0,
    "q" => 0,
    "r" => 0,
    "s" => 0,
    "t" => 0,
    "u" => 0,
    "v" => 0,
    "w" => 0,
    "x" => 0,
    "y" => 0,
    "z" => 0
}

loop do
    input = gets
    if input == nil
        break
    else
        input = input.chomp.downcase.split("").map do |s| s.to_s end
        input.each do |n|
            alphabet[n] = alphabet[n].to_i + 1
        end
    end
end

("a".."z").each do |n|
    puts "#{n} : #{alphabet[n]}"
end