foo.cc:21:1: error: extended character   is not valid in an identifier
   21 |  
      | ^
foo.cc: In function 'int main()':
foo.cc:10:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   10 |     for (int i = 0; i < s1.length(); i++)
      |                     ~~^~~~~~~~~~~~~
foo.cc: At global scope:
foo.cc:21:1: error: '\U000000a0' does not name a type
   21 |  
      | ^

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