C++ program to find smallest,largest,product and average using class

#include<iostream.h>
#include<conio.h>
int main()
{
clrscr();
int num1,num2,num3,smallest,largest; //declaration
cout<<"Input three integers:";//prompt
cin>>num1>>num2>>num3;//input
largest=num1; //assume first number is largest
if(num2>largest)//is num2 larger?
largest=num2; //assume second number is larger
if(num3>largest)//is num3 largest?
largest=num3; //assume num3 is larger
smallest=num1; //assume num1 is smallest
if(num2<smallest)
smallest=num2;
if(num3<smallest)
smallest=num3;
cout<<"Sum is:\n"<<num1+num2+num3<<endl;
cout<<"Average is:\n"<<(num1+num2+num3)/3<<endl;
cout<<"\nProduct is:\n"<<num1*num2*num3<<"\nSmallest is:\n"<<smallest<<"\nLargestis:\n"<<largest<<endl;
getch();
return 0;
}