Here is my solution:

public class Solution {
public static void main(String args[] ) throws Exception {
    /* Enter your code here. Read input from STDIN. Print    output to STDOUT */
    Scanner scn = new Scanner(System.in);
    String s = scn.nextLine();
    Set<Character> setValue = new HashSet<Character>(); 

    String replaced = s.replaceAll(" ","").toLowerCase();
     for(int i = 0; i<replaced.length(); i++)
     {
         setValue.add(replaced.charAt(i));
     }

    if(seValue.size() == 26)
    {
        System.out.print("pangram");
    }
    else
    {
        System.out.print("not pangram");
    }
}

}