a=int(input("enter the marks"))
if(a>=90):
	print("GRADE-A+")
elif(a>=80):
	print("GRADE-A")
elif(a>=70):
	print("GRADE-B+")
elif(a>=60):
	print("GRADE-B")
elif(a>=50):
	print("GRADE-C+")
elif(a>=40):
	print("GRADE-C")
elif(a>=35):
	print("GRADE-D")
else:
	print("FAILED")