cnt = Array.new(26,0)
while str = gets
    str.each_char { |c|
        if (c>='a' && c<='z') || (c>='A' && c<='Z')
            cnt[c.downcase.ord-'a'.ord]+=1
        end
    }
end

26.times { |i|
    print( (i+'a'.ord).chr, " : ",cnt[i],"\n")
}