#Exercise 7 from Python Programming Word Doc
mark=0
grade=""
while mark >= 0:
    mark =int(input("Enter a mark"))
    if mark > 90:
        grade = " - Distinction"
    elif mark > 80:
        grade = " - Merit"
    elif mark > 45:
        grade = " - Pass"
    elif mark >0:
        grade =" - Fail"
    if mark>0:
        print("Mark = ",mark,"Grade ",grade)
print("That's all")