To Print Second Maximum Number in C

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

/*take input from user again and again till user enter a negitive number after this print the second maximum number*/


void main()
{
int max=0, min=0, num=0;


clrscr();


while (num>=0)
{
printf("enter the value of number");
scanf("%d",&num);

if(num>0)
{
if(num>max)
{
min=max;
max=num;
}

else if(num>min)
{
min=num;
}

}

else if (num<0)
{
break;
}
}

printf("second maximum number%d",min);

getch();
}