View Compilation Error

0_0_17008369_8278.cpp: In function 'int main()':
0_0_17008369_8278.cpp:29:34: error: cannot convert 'std::deque<_Tp, _Alloc>::empty<int, std::allocator<int> >' from type 'bool (std::deque<int>::)() const noexcept' to type 'bool'
    while (!deq1.empty() && !deq2.empty && deq1.front() - deq2.front() >= k){
                                  ^
0_0_17008369_8278.cpp:29:34: error: in argument to unary !