foo.c: In function 'main':
foo.c:5:4: error: 'cout' undeclared (first use in this function)
    5 |    cout<<"A"<<endl<<"AAA"<<endl<<"AAAAA"<<endl<<"AAAAAAA"<<endl;
      |    ^~~~
foo.c:5:4: note: each undeclared identifier is reported only once for each function it appears in
foo.c:5:15: error: 'endl' undeclared (first use in this function)
    5 |    cout<<"A"<<endl<<"AAA"<<endl<<"AAAAA"<<endl<<"AAAAAAA"<<endl;
      |               ^~~~

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