september.cpp: In function 'int solve(int, int, std::vector<int>, std::vector<std::vector<int> >)':
september.cpp:19:9: error: no match for 'operator!' (operand type is '__gnu_cxx::__alloc_traits<std::allocator<std::unordered_set<int> >, std::unordered_set<int> >::value_type' {aka 'std::unordered_set<int>'})
19 | if (!g[F[S[0][i]]]].size()){
september.cpp:19:9: note: candidate: 'operator!(bool)' (built-in)
september.cpp:19:9: note: no known conversion for argument 1 from '__gnu_cxx::__alloc_traits<std::allocator<std::unordered_set<int> >, std::unordered_set<int> >::value_type' {aka 'std::unordered_set<int>'} to 'bool'
september.cpp:19:23: error: expected ')' before ']' token
19 | if (!g[F[S[0][i]]]].size()){
| ~ ^
| )
september.cpp:19:23: error: expected primary-expression before ']' token