C Program that show marks of students in Ascending Order

#include<stdio.h>
#include<conio.h>

struct student
{
    int Roll_No,Marks;
    char Fname[25];
}stud[100],t;

void main()
{
    int i,j,n;
    printf("Enter how many students?\n");
    scanf("%d",&n);
    printf("enter students information in the sequence of Roll Numbers, First Names and Marks\n");

// Take Students' information from the user …