/in/foo.cc:7:2: error: 'next' does not name a type
  next,to,flow,cost;
  ^~~~
/in/foo.cc: In function 'void add(int, int, int, int)':
/in/foo.cc:17:2: error: 'b' was not declared in this scope
  b[++cnt].next=head[op];
  ^
/in/foo.cc: In function 'bool bfs()':
/in/foo.cc:29:31: error: 'b' was not declared in this scope
   for(int i=head[now];i!=-1;i=b[i].next)
                               ^
/in/foo.cc: In function 'int dfs(int, int)':
/in/foo.cc:42:28: error: 'b' was not declared in this scope
  for(int i=head[u];i!=-1;i=b[i].next)
                            ^
/in/foo.cc:41:6: warning: unused variable 'f' [-Wunused-variable]
  int f,flow=0;
      ^
/in/foo.cc:41:8: warning: unused variable 'flow' [-Wunused-variable]
  int f,flow=0;
        ^~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:55:28: error: 'siseof' was not declared in this scope
  memset(head,-1,siseof(head));
                            ^
/in/foo.cc: In function 'int dfs(int, int)':
/in/foo.cc:46:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^