class School:

    def __init__(self):
        self.students = []

    def findTopper(self):
        # add logic to find student with highest marks
        topper = self.students[0]
        return topper

    def addStudent(self, student):
        self.students.append(student)


class Student:

    def __init__(self, name, marks):
        self.name = name
        self.marks = marks
        self.grade = ""

    def calculateGrade(self):
        if self.marks < 40:
            self.grade = "D"
        elif self.marks < 60:
            self.grade = "C"
        elif self.marks < 80:
            self.grade = "B"
        else:
            self.grade = "A"

    def displayGrade(self):
        print(self.name)
        print("Grade -")
        print(self.grade)


school1 = School()

for i in range(1):
    name = input("Enter Name: ")
    marks = int(input("Enter Marks: "))

    st = Student(name, marks)
    st.calculateGrade()
    school1.addStudent(st)


topper = school1.findTopper()

print("Topper is -")
print(topper.name)