直接加起来就好了，呵呵O(∩_∩)O~
#include<cstdio>
int main()
{
	int ans=0;
	char ch=0;
	while(scanf("%c",&ch)!=EOF)
	{
		if(ch=='\n')
		{
			if(ans==0)break;
			ans%=9;
			if(ans!=0)printf("%d\n",ans);
			else printf("9\n");
			ans=0;
		}
		else ans+=(ch-'0');
	}
	return 0;
}