#lines = [
#        "This is a pen."
#]

lines = $stdin.read #.split("\n")

#lines.each do |l|

        array = lines.chomp.downcase!.each_codepoint.to_a
        sum_h = (96..122).to_a.map{ |c| [c, 0]}.to_h
        array.each{|i| sum_h[i] += 1 unless sum_h[i].nil? }

        sum_h.sort.select{|k,v| 96 < k && k < 123 }.map do |k,v|
                puts "#{k.chr} : #{v}"
        end
#end