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.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = "";  
        String text;
        String Lower_text;
        int count = 0;
        int textlen;
        String testtext;        
        while(true){
            text = sc.next();
            Lower_text = text.toLowerCase();
            str = str + Lower_text;
            
            textlen = text.length();
            testtext = text.substring(textlen-1);
            if(testtext.equals(".")) break;//Judging wether text contains "." or not            
        }
        char[] c = str.toCharArray();
        int[] alphabet;
        alphabet = new int[26];
        
        for(count=0;count<str.length()-1;count++){
            alphabet[(c[count]-'a')]++;            
        }
        for(count=0;count<26;count++){
            System.out.println((char)(count+'a') + " : " + alphabet[count]);
        }
        sc.close();
    }
}