#include<stdio.h>
#include<conio.h>
int product(int,int);
void main()
{
 int a,b;
 clrscr();
 printf("enter two numbers");
 scanf("%d%d",&a,&b);
 printf("product of two numbers is %d",product(a,b));
 getch();
 }

 int product(int a,int b)
{
 if(b==1)return a;
 else
 return(a+product(a,--b));
}