Nomor 2 if else

package tugas_elseif_scanner;
import java.util.Scanner;
/**
 *
 * @author kalvin jr
 */
public class Tugas_elseif_scanner {
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
    Scanner input = new Scanner(System.in);
    String nama,stb,almt,grade,ket;
    int nt,nm,nf;
    double na;

         System.out.print("Masukkan Stambuk : ");
         stb = input.nextLine();
         System.out.print("Masukkan Nama : ");
         nama = input.nextLine();
         System.out.print("Masukkan alamat : ");
         almt = input.nextLine();
         System.out.print("Masukkan Nilai Tugas :");
         nt =Integer.parseInt(input.nextLine());
         System.out.print("Masukkan Nilai Mid : ");
         nm =Integer.parseInt(input.nextLine());
         System.out.print("Masukkan Nilai Final : ");
         nf =Integer.parseInt(input.nextLine());

         na=((0.3*nt)+(0.3*nm)+(0.4*nf));

         if((na>=80) && (na<=100)){
             grade = "A";
             ket ="Sangat Baik";
         }
         else if((na>=65) && (na < 80)){
             grade = "B";
             ket = "Baik";
         }
         else if((na>=50)&&(na<65) ){
             grade = "C";
             ket = "Kurang";
         }
         else if((na>=35) && (na <50 )){
             grade = "D";
             ket = "Sangat Kurang";
         }
         else {
        grade = "E";
        ket = "Eror";
    }
    System.out.println("\n\n");
    System.out.println("=============Menghitung Nilai Mahasiswa===========");
    System.out.println("\n");
    System.out.println("STAMBUK\t\t: "+stb);
    System.out.println("NAMA\t\t: "+nama);
    System.out.println("ALAMAT\t\t: "+almt);
    System.out.println("NILAI TUGAS\t: "+nt);
    System.out.println("NILAI MID\t: "+nm);
    System.out.println("NILAI FINAL\t: "+nf);
    System.out.println("NILAI AKHIR\t: "+na);
    System.out.println("NILAI HURUF\t: "+grade);
    System.out.println("KETERANGAN\t: "+ket);

        // TODO code application logic here
    }