foo.c: In function 'main':
foo.c:9:5: error: 'cout' undeclared (first use in this function)
    9 |     cout<<"xiao wang shi huai dan"<<endl;
      |     ^~~~
foo.c:9:5: note: each undeclared identifier is reported only once for each function it appears in
foo.c:9:37: error: 'endl' undeclared (first use in this function)
    9 |     cout<<"xiao wang shi huai dan"<<endl;
      |                                     ^~~~

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