/in/foo.cc: In function 'int main()':
/in/foo.cc:12:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   12 |                 for(int i=0;i<=s.size();i++){
      |                             ~^~~~~~~~~~
/in/foo.cc:13:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |                 if(i==s.size())  { if(cnt==4) {cout<<"OK"<<endl;
      |                    ~^~~~~~~~~~