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 JAVA (judge verdict: Accepted)

import java.io.*;

public class Main{

    public static void main(String[]args)throws IOException{

        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        char[] alfa = {'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
                        'n','o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z'};
        int[] counter = new int[26];
        String str;

        while((str = br.readLine()) != null){

            //?°????????????±?????????????§£
            str = str.toLowerCase();
            char[] strArray = str.toCharArray();

            for(int i=0; i<strArray.length; i++){
                for(int k=0; k<26; k++){
                    if(alfa[k] == strArray[i]) counter[k]++;
                }
            }
        }
        //??????
        for(int i=0; i<26; i++){
            System.out.println(alfa[i] +" : "+ counter[i]);
        }
    }   
}