If two students have same grades your have to sort them by ID

Question

First line contains n(0 < n < 1001).
Then n lines inputed in given format:
First number - student's ID
Second number - the final grade of the student

Output:
n lines sorted by grades(Note:If two students have same grades your have to sort them by ID)

INPUT OUTPUT
3 25 90.1
20 80 30 90.1
30 90.1 20 80
25 90.1

https://code.sololearn.com/cFn6vpr72TeA/#cpp