/**

*The sentence 'A quick brown fox jumps over the lazy dog' contains every single letter in the

*alphabet. Such sentences are called pangrams. You are to write a program, which takes a

*sentence, and returns all the letters it is missing (which prevent it from being a pangram).

*You should ignore the case of the letters in sentence, and your return should be all lower case

*letters, in alphabetical order. You should also ignore all non US-ASCII characters.In case

*the input sentence is already a pangram, print out the string NULL

*/

import java.io.File;

import java.io.FileNotFoundException;

import java.util.Scanner;

public class pangrams {

public static final String abc = "abcdefghijklmnopqrstuvwxyz";

public static void main(String[] args) {

read(args[0]);

}

public static void read(String f) {

File file = new File(f);

try {

Scanner in = new Scanner(file);

while (in.hasNextLine()) {

proc(in.nextLine().toLowerCase());

}

} catch (FileNotFoundException e) {

}

}

private static void proc(String pan) {

String str = "";

for (int i = 0; i < abc.length(); i++) {

String ch = "" + abc.charAt(i);

if (!pan.contains(ch)) {

str += ch;

}

}

if (str.length() == 0) {

System.out.println("NULL");

} else

System.out.println(str);

}

}