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: Accepted)

using System;

class Program
{
    static void Main(string[] args)
    {
        int[] aryCount = new int[26];
        string alpha = "abcdefghijklmnopqrstuvwxyz";

        while (true)
        {
            string inputData = Console.ReadLine();

            if (inputData == null || inputData.Length == 0)
            {
                break;
            }

            for (int i = 0; i < inputData.Length; i++ )
            {
                if (char.IsLower(inputData[i]))
                {
                    int num = inputData[i] - 'a';
                    aryCount[num]++;
                }
                else if (char.IsUpper(inputData[i]))
                {
                    int num = inputData[i] - 'A';
                    aryCount[num]++;
                }
            }
        }

        for (int i = 0; i < aryCount.GetLength(0); i++)
        {
            Console.WriteLine(alpha[i] + " : " + aryCount[i]);
        }

    }
}