Problem:
Counting Characters

Write a program which counts and reports the number of each alphabetical letter. Ignore the case of characters.

Input

A sentence in English is given in several lines.

Output

Prints the number of alphabetical letters in the following format:

a : The number of 'a'
b : The number of 'b'
c : The number of 'c'
.
.
z : The number of 'z'

Constraints

The number of characters in the sentence < 1200

Sample Input

This is a pen.

Sample Output

a : 1
b : 0
c : 0
d : 0
e : 1
f : 0
g : 0
h : 1
i : 2
j : 0
k : 0
l : 0
m : 0
n : 1
o : 0
p : 1
q : 0
r : 0
s : 2
t : 1
u : 0
v : 0
w : 0
x : 0
y : 0
z : 0

Solution in C# (judge verdict: Wrong Answer)

using System;
using System.Collections.Generic;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Text;

namespace LogicSummoner
{
    class Program
    {
        static void Main(string[] args)
        {
            var result = Enumerable.Range(0, 'z' - 'a' + 1)
                .Select(x => x + 'a')
                .ToDictionary(x => x, x => 0);

            while (true)
            {
                var line = Console.ReadLine();
                if (line == null)
                {
                    break;
                }

                foreach (var l in line.Trim())
                {
                    var a = 'A' <= l && l <= 'Z' ? l - 'A' + 'a' : l;
                    if (result.ContainsKey(a))
                    {
                        result[a]++;
                    }
                }

                foreach (var item in result)
                {
                    System.Console.WriteLine("{0} : {1}", (char)item.Key, item.Value);
                }
            }
        }

        //static StreamReader Console = new StreamReader("input.txt");

        static int GetNumber()
        {
            return int.Parse(Console.ReadLine().Trim());
        }

        static double GetDounble()
        {
            return double.Parse(Console.ReadLine().Trim());
        }

        static int[] GetNumbersInt(int n = 0)
        {
            return Console.ReadLine().Trim().Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries).Select(x => int.Parse(x)).ToArray();
        }

        static long[] GetNumbersLong(int n = 0)
        {
            return Console.ReadLine().Trim().Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries).Select(x => long.Parse(x)).ToArray();
        }

        static double[] GetNumbersDouble(int n = 0)
        {
            return Console.ReadLine().Trim().Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries).Select(x => double.Parse(x)).ToArray();
        }

        static string[] GetStrings(int n = 0)
        {
            return Console.ReadLine().Trim().Split(new[] { " " }, StringSplitOptions.RemoveEmptyEntries).ToArray();
        }
    }
}