foo.cc: In function 'int main()':
foo.cc:13:9: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   13 |  while(i<s.length())
      |        ~^~~~~~~~~~~
foo.cc:16:11: warning: comparison of integer expressions of different signedness: 'int' and 'const size_type' {aka 'const long unsigned int'} [-Wsign-compare]
   16 |   if(index!=s.npos)

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