foo.cc: In function 'int main()':
foo.cc:8:10: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 | for(i=0;i<a.size();i++)
      |         ~^~~~~~~~~
foo.cc:12:11: 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(i=0;i<a.size();i++)
      |          ~^~~~~~~~~
foo.cc:16:5: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   16 | if(i==a.size()) cout<<"Yes";
      |    ~^~~~~~~~~~

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