/in/foo.cc: In function 'int main()':
/in/foo.cc:22:5: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
   if(z==2) 
     ^

VJ4Error('ProblemDataNotFoundError', '题目 1006 的数据未找到。', 'FtOJ', 1006)