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;

namespace ITP1_8_C
{
    class Program
    {
        static void Main()
        {
            int[] sum = new int[26];
            while(true)
            {
                string sentence;
                if((sentence = Console.ReadLine()) == null) break;
                char[] schar = sentence.ToLower().ToCharArray();
                for(int i = 0; i < schar.Length; i++)
                {
                    if(schar[i] != ' ' && schar[i] != '.') sum[schar[i] - 'a']++;
                }
            }
            for(int i = 0; i < sum.Length; i++) Console.WriteLine(((char)('a' + i)) + " : " + sum[i]);
        }
    }
}