View Compilation Error

0_0_37338569_30452.cpp: In function 'int main()':
0_0_37338569_30452.cpp:86:30: error: no matching function for call to 'MaxClique::solve()'
         cout << solver.solve() << '\n';
                              ^
0_0_37338569_30452.cpp:86:30: note: candidate is:
0_0_37338569_30452.cpp:59:7: note: int MaxClique::solve(std::bitset<50ull>)
   int solve(bitset<kN> mask) {  // vertex mask
       ^
0_0_37338569_30452.cpp:59:7: note:   candidate expects 1 argument, 0 provided