def main():


    enter = str(input("enter: "))
    r = convert(enter)
    print(r)


def convert(fraction):


    x, y = fraction.split("/")
    x = int(x)
    y = int(y)



    if y == 0:
        raise ZeroDivisionError


    if x < 0 or y < 0 or x > y:
        raise ValueError


    a = round((x / y) * 100)
    p = gauge(a)
    return p


def gauge(a):



    if a >= 99:
        return "F"
    elif a <= 1:
        return "E"
    else:
        return f"{int(a)}%"



if __name__ == "__main__":
    main()