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.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Counting_Characters
{
    class Program
    {
        static void Main(string[] args)
        {
            string input = Console.ReadLine().ToLower();

            List<char> letter = new List<char>();
            int[] count = new int[26];

            for (char i = 'a'; i <= 'z'; ++i)
            {
                letter.Add(i);
            }

            for (int i = 0; i < 26; ++i)
            {
                count[i] = 0;
            }

            foreach (char c in input)
            {
                foreach (char c2 in letter)
                {
                    if (c == c2)
                    {
                        ++count[letter.IndexOf(c2)];
                    }
                }
            }

            int cc = 0;

            foreach (char item in letter)
            {                
                Console.WriteLine(item + " : " + count[cc]);
                ++cc;
            }

            
        }
    }
}