public class MyClass{

	public static void main(String[]args) {

		int Grade = 60;
		switch(Grade)
		{
		case 10 :
			System.out.println("IG");
		break;
		case 30 :
			System.out.println("VG");
			break;
		case 60 :
			System.out.println("MVG");
			break;
		}

		}

	}