class School:

    def __init__(self, name):
        self.name = name
        self.db = {}

    def grade(self, grd):
        if grd not in self.db:
            return set()
        for grade in self.db:
            if grd == grade:
                return self.db[grd]

    def add(self, student, grd):
        if grd in self.db:
            self.db[grd].add(student)
        else:
            self.db[grd] = {student}

    def sort(self):
        for grade in self.db:
            self.db[grade] = tuple(sorted(self.db[grade]))
        return self.db

e625923e52680a83843e8f4ac58f49325702bbdb
class School:
    <mask token>
    <mask token>

    def add(self, student, grd):
        if grd in self.db:
            self.db[grd].add(student)
        else:
            self.db[grd] = {student}
    <mask token>

class School:

    def __init__(self, name):
        self.name = name
        self.db = {}
    <mask token>

    def add(self, student, grd):
        if grd in self.db:
            self.db[grd].add(student)
        else:
            self.db[grd] = {student}
    <mask token>

class School:

    def __init__(self, name):
        self.name = name
        self.db = {}

    def grade(self, grd):
        if grd not in self.db:
            return set()
        for grade in self.db:
            if grd == grade:
                return self.db[grd]

    def add(self, student, grd):
        if grd in self.db:
            self.db[grd].add(student)
        else:
            self.db[grd] = {student}
    <mask token>

class School:

    def __init__(self, name):
        self.name = name
        self.db = {}

    def grade(self, grd):
        if grd not in self.db:
            return set()
        for grade in self.db:
            if grd == grade:
                return self.db[grd]

    def add(self, student, grd):
        if grd in self.db:
            self.db[grd].add(student)
        else:
            self.db[grd] = {student}

    def sort(self):
        for grade in self.db:
            self.db[grade] = tuple(sorted(self.db[grade]))
        return self.db
