C++ Program .Write a program to argument & return value

#include<stdio.h>
#include<conio.h>
int add(int a,int b);
void main()
{
int a,b,ans;
clrscr();
printf("\n enter the value of a");
scanf("\n %d",&a);
printf("\n enter the value of b");
scanf("\n %d",&b);
ans=add(a,b);
printf("\n addition is n%d",ans);
getch();
}
int add(int a1,int b1)
{
int c;
c=a1+b1;
return c;
}