program of subtraction in c++

#include<iostream.h>
#include<conio.h>
int main()
{
clrscr();
int a,b,sub;
cout<<"enter the value a:";
cin>>a;
cout<<"enter the value b:";
cin>>.b;
sub = a - b;
cout<<"the sub of given value is:";
cout<<sub;
getch();
return(0);
}