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: Time Limit Exceeded)

#include <iostream>
#include <cctype>
#include <string>
using namespace std;

int main(int argc, const char * argv[]) {
    string sentence;
    int alpha[26]={0};

    //getline(cin,sentence);
    while (1) {
        getline(cin,sentence);
    for (int i=0; i<sentence.size(); i++) {
        if (isalpha(sentence[i])) {  //文字かどうか判別
            if(isupper(sentence[i])) { //大文字の時↓
                sentence[i] = (char)tolower(sentence[i]); //小文字を返す
            }
        }
        //cout << sentence[i];
    }
    for(int j=0;j<=(int)sentence.size();j++){
        alpha[sentence[j] -'a']++; //sentenceに値がある時+する
    }
    }
    for(char ch='a';ch<='z';ch++){
        cout<<ch<<" : "<<alpha[ch-'a']<<endl;
    }
    return 0;
}