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: Runtime Error)

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

namespace Prac
{
    class Prog
    {
        public static void Main()
        {
            StringBuilder input = new StringBuilder();
            String temp = "";
          
            while (true)
            {
                temp = Console.ReadLine().ToLower();
                
                input.Append(temp);
                if (temp.Last() == '.')
                    break;
            }
            var input2 = input.ToString().ToCharArray();
            for (var i = 'a'; i <= 'z'; i++)
            {
                Console.WriteLine(i.ToString() + " : " + input2.Count(x => x == i).ToString());
                
            }
           
        }
    }
}