foo.cc: In function 'int main()':
foo.cc:22:37: warning: comparison of integer expressions of different signedness: 'll' {aka 'long long int'} and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   22 |                         for(ll t=0;t<c.size();t++)
      |                                    ~^~~~~~~~~

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