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: Runtime Error)

import java.io.*;
import java.util.*;

class Main {

    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        HashMap<Character, Integer> map = new HashMap<>();
        char c = 'a';
        for (int i = 0; i < 26; i++) {
            map.put((char) (c + i), 0);
        }
        char[] c_array;
        String str;
        do {
            str = br.readLine();
            c_array = str.toCharArray();
            for (char dc : c_array) {
                if ('A' <= dc && dc <= 'Z') {
                    dc = (char) (dc - 'A' + 'a');
                }
                if (map.containsKey(dc)) {
                    map.put(dc, map.get(dc) + 1);
                }
            }
        } while (c_array[c_array.length - 1] != '.');

        for (int i = 0; i < 26; i++) {
            System.out.println((char) ('a' + i) + " : " + map.get((char) ('a' + i)));
        }
    }
}