y := log (x) / log (3)  / (x + x * x);

#include <stdio.h> 
#include <conio.h>
struct student
{
    char name[30];
    int group;
    int age;
};
int main()
{
    struct student stud[10];
    student temp;
    int i,j,n;

printf("Number of students:");
scanf("%d", &n);
//Ввод данных
    for(i=0;i<n;i++)
    {
       printf("Name:");
       scanf("%s", stud[i].name);
       printf("Age:");
       scanf("%d", &stud[i].age);
       printf("Number of group:");
       scanf("%d", &stud[i].group);
    }
//Сортировка
    for (i=0; n-1; i++) 
    {
		for (j=0; n-1; i++) 
        {
			if (stud[j].age > stud[j+1].age)
                {
				temp=stud[j];
				stud[j] = stud[j+1];
				stud[j+1] = temp;
                } 
        }
    } 
     getch();
}