百练 2764 数根

题目链接：http://bailian.openjudge.cn/practice/2764

# include <stdio.h>int main(){char s[10002];int n;while(scanf("%s",s)==1&&s[0]!='0'){n=0;for(int i=0;s[i]!=0;i++){n+=s[i]-'0';}printf("%d\n",(n-1)%9+1);}return 0;}