#include<iostream.h>
#include<conio.h>
int main()
{
long unsigned int n,d,sum, i;
clrscr();
cout<<"Enter a number : ";
cin>>n;
abc :
sum = 0;
do
{
d = n % 10 ;
sum = sum + d;
n = n / 10;
}
while (n!=0);
if (sum > 9)
{
n = sum;
goto abc;
}
else
cout<<"The result is : "<< sum;
getch();
return 0;
}