num=int(input('enter mark'))

if num>=90:
    print('grade is A+')
elif num>=80:
    print('grade is A ')
elif num>=70:
    print('grade is B+ ')
elif num >= 60:
    print('grade is B ')
elif num >= 50:
    print('grade is C+')
elif num >= 40:
    print('grade is C')
else:
    print('Failed')