foo.cc: In function 'int main()':
foo.cc:32:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for(int i=0; i<str.size(); i++)
      |                      ~^~~~~~~~~~~
foo.cc:38:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |                         while(j < str.size() && isdigit(str[j]))
      |                               ~~^~~~~~~~~~~~

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