View Compilation Error

0_0_38984781_27482.cpp: In function 'int main()':
0_0_38984781_27482.cpp:23:37: error: expected primary-expression before 'long'
   23 |                                 if (long long (sqrt(c/2))==sqrt(c/2)) {
      |                                     ^~~~
0_0_38984781_27482.cpp:23:37: error: expected ')' before 'long'
   23 |                                 if (long long (sqrt(c/2))==sqrt(c/2)) {
      |                                    ~^~~~
      |                                     )