foo.cc: In function 'void work(std::__cxx11::string, int)':
foo.cc:8:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<s.size();i++)
              ~^~~~~~~~~
foo.cc: At global scope:
foo.cc:35:1: error: expected declaration before '}' token
 }
 ^

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