#include<stdio.h>
#include<conio.h>
int main()
{
	int sum=0,n,r;
	printf("enter any number\n");
	scanf("%d",&n);
	do
	{
		sum=0;
		while(n!=0)
		{
			r=n%10;
			sum=sum+r;
			n=n/10;
		}
		n=sum;
	}while(n>9);
printf("\n the required result is=%d",n);
getch();
}