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: Memory Limit Exceeded)

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

namespace AizuOnline
{
    internal class Program
    {
        private static void Main(string[] args)
        {
            var a = "abcdefghijklmnopqrstuvwxyz";
            var dic = new Dictionary<char, int>();
            foreach (var A in a)
            {
                dic[A] = 0;
            }

            var X = new List<string>();
            var count = 0;
            while (true)
            {
                var r = Console.ReadLine();
                if (r == string.Empty)
                {
                    break;
                }
                X.Add(r);
                count++;
            }

            foreach (var x in X)
            {
                foreach (var c in x.ToCharArray())
                {
                    var C = char.ToLower(c);
                    int num;
                    if (dic.TryGetValue(C, out num))
                    {
                        dic[C] = ++num;
                    }
                }
            }

            foreach (var p in dic)
            {
                Console.WriteLine(p.Key + " : " + p.Value);
            }
            Console.ReadLine();
        }
    }
}