import sys

numA = numB = numC = numD = numF = 0

for grade in open(sys.argv[1], "r"):
    grade = int(grade)
    if ((grade <0 ) or (grade > 100)):
        print grade, "is not a valid mark"
    elif (grade < 65):
        if (55 <= grade < 65):
            numC += 1
        elif (50 <= grade < 55):
            numD += 1
        else:
            numF += 1
    else:
        if (80 <= grade <= 100):
            numA += 1
        else:
            numB += 1

print "Grades: ", numA, "As /", numB, "Bs / ", numC, "Cs / ", \
      numD, "Ds / ", numF, "Fs / "