Students and courses models in django--many-to-many relation

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model

Django

Sir, I am trying to make students and courses relationship but cannot do that

Thats the Students Model:

class Student(models.Model):
    GENDER = (
        ('F', 'Female'),
        ('M', 'Male'),
        ('O', 'Other'),
    )
    std_ID = models.CharField(max_length=12, primary_key=True, default='16201519-001')
    std_name = models.CharField(max_length=50, default='')
    std_gender = models.CharField(max_length=1, choices=GENDER, default='M')
    std_class = models.CharField(max_length=50, default='')

Thats the Courses Model:

class Courses(models.Model):
    Credits = (
        ('1', 'One'),
        ('2', 'Two'),
        ('3', 'three'),
        ('4', 'four'),
        ('6', 'Six'),
    )
    c_code = models.CharField(max_length=20, primary_key=True, default='CS-202')
    c_name = models.CharField(max_length=50)
    c_creditsHours = models.CharField(max_length=1, choices=Credits)
    courses = models.ManyToManyField(Courses)

What I have tried:

Here you can see, I am using ManyToManyField but when
First, I use the ManyToManyField, then thats show the relation ship in the side of courses but not at person side.
Second, by using the ManyToManyField, All the students already selected but i want to select some of them but cannot do that.
So please tell me how we can do that.