foo.cc: In function 'void query::dfs1(int)':
foo.cc:62:30: warning: left operand of comma operator has no effect [-Wunused-value]
   for(re i=head[x],y;i,y=go[i];i=nxt[i])dfs1(y);
                              ^
foo.cc: In function 'void init()':
foo.cc:78:6: warning: unused variable 'p' [-Wunused-variable]
  int p=0,u=0,n=0;
      ^
foo.cc:79:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%s",s+1);ll=strlen(s+1);
  ~~~~~^~~~~~~~~~

正在同步测试数据，请稍后
自豪的采用HydroJudge(https://github.com/hydro-dev/Hydro)进行评测。