Just While$-$loop. otherwise no credit.

Question: Calculate the average of students:

$1$ ask user how many students are in the class.

$2.$ fot each student ask how many grades do you bave

$3.$ ask user to enter grades for that student and for each grade validate it

$4$ after getting valid grades for each student then calculate the average for that student.

Sample output:

How many students are in the class: $2$

Student I: how many grades you have: $3$

Student$1,$ Grade$1$: $90$

Student, Grade$2$: $-1$

Error: Invalid grade enter again.

Student$1,$ Grade$2$:$90$

Student $1,$ Grade$3$:$90$

Average for Student $1$ is $90$

Student $2$: How masy grades you have? $2$

Student $2,$ Grade $2$:$80$

Student $2,$ Grade $2$:$80$

The average for student $2$ is $80$

End of the program