foo.cc: In function 'void solution(std::__cxx11::string)':
foo.cc:17:6: error: expected ';' before 'for'
      for(int i = 0; i < num; i++)
      ^~~
foo.cc:17:21: error: 'i' was not declared in this scope
      for(int i = 0; i < num; i++)
                     ^

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