public class p178_4
{
  public static void main(String[] args)
  {
  	int A=0,B=0,C=0,D=0,F=0;//A to F is the ranks.
  	int grade=0;
  	
  	System.out.println("Please enter the exam scores one each line."+
  	"Input \"-1\" to end");
  	
  	do{
  	   int grade=SavitchIn.readLine();
  	
  	   if(grade<0||grade>100){
     	System.out.println("Sorry!There must be something wrong!"+
  	    "There shouldn't be any grade greater than 100 or smaller than 0."+
     	"Please try again:");
  	    grade=SavitchIn.readLine();
  		  	}
  		  	
    	do{
    		int grade=SavitchIn.readLine();
  	    	if(grade<=100&&grade>=90)
  		      A++;
  	     	else if(grade<=89&&grade>=80)
  		      B++;
  		    else if(grade<=79&&grede>=70)
  		      C++;
     		else if(grade<=69&&grade>=60)
  	    	  D++;
  		    else
  		      F++;
  		      }
      }
  	  while(grade!=-1);
  	System.out.pringln("Total number of grades=")
  }
}