grading2

Scanner kb = new Scanner(in);
		int ma = 0;
		int mi = 0;
		int ot = 0;
		int f = 1;
		int a = 0;
		int i = 0;
		int t = 0;
		while (f>0)
		{
			out.println("Enter the grade:");
			int grade = kb.nextInt();
			if(grade<0)
				break;
			out.println("Enter grade catagory(Ma = major,Mi = minor,Oth = other");
			String cat = kb.next();
			if(cat.equals("Ma"))
			{
				ma += grade;
				a++;
			}
			else if(cat.equals("Mi"))
			{
				mi += grade;
				i++;
			}
				else if(cat.equals("Oth"))
			{
				ot += grade;
				t++;
			}
		}
		int mao = ma/a;
		int mio = mi/i;
		int oto = ot/t;
		double avg = (mao*.7)+(mio*.2)+(oto*.1);
		out.println();
		out.println("Major average\t\t"+mao);
		out.println("Minor average\t\t"+mio);
		out.println("Other average\t\t"+oto);
		out.println("Overall average\t\t"+String.format("%.1f",avg));