foo.cc: In function 'int main()':
foo.cc:9:5: error: 'cout' was not declared in this scope
    9 |     cout<<"xiao wang shi huai dan"<<endl;
      |     ^~~~
foo.cc:9:37: error: 'endl' was not declared in this scope
    9 |     cout<<"xiao wang shi huai dan"<<endl;
      |                                     ^~~~
foo.cc:12:5: error: 'cout' was not declared in this scope
   12 |     cout<<"xiao gu shi hao ren"<<endl;
      |     ^~~~
foo.cc:12:34: error: 'endl' was not declared in this scope
   12 |     cout<<"xiao gu shi hao ren"<<endl;
      |                                  ^~~~

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