View Compilation Error

0_0_35975981_11698.cpp: In function 'int main()':
0_0_35975981_11698.cpp:23:12: error: cannot convert 'std::priority_queue<_Tp, _Sequence, _Compare>::empty<arr, std::vector<arr, std::allocator<arr> >, std::less<arr> >' from type 'bool (std::priority_queue<arr>::)() const' to type 'bool'
   while(!q.empty){
            ^
0_0_35975981_11698.cpp:23:12: error: in argument to unary !