Compilare: main.cpp: In function 'int main()': main.cpp:82:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 82 | for(int i=3;i<sol.size()-1;i++) | ~^~~~~~~~~~~~~