> #include <iostream>
> using namespace std;
> int f(int x)
> {
> 	if(x%9)
> 		return x%9;
> 	else
> 		return 9;
> }
> int main()
> {
> 	int m;
> 	while(1)
> 	{
> 		cin>>m;
> 		if(m)
> 			cout<<f(m)<<endl;
> 		else
> 			break;
> 	}
> 	return 0;
> }