if文で学生の成績区分を書き、学生の成績等級を出力します.

package temp;
import java.util.Scanner;

public class Grade {
    public static void main(String[] args) {
        Scanner scanner=new Scanner(System.in);
        System.out.println("      :");
        int num=scanner.nextInt(); 
        if(num>=90 && num<=100) 
    	    System.out.println("  ");
        if(num>=80 && num<90)
    	    System.out.println("  ");
        if(num>=70 && num<80)
    	    System.out.println("  ");
        if(num>=60 && num<70)
    	    System.out.println("  ");
        if(num<60)
    	    System.out.println("   ");
     }
}