foo.cc: In function 'int main()':
foo.cc:6:1: error: 'cin' was not declared in this scope
    6 | cin>>a>>b>>c;
      | ^~~
foo.cc:2:1: note: 'std::cin' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
    1 | #include<cmath>
  +++ |+#include <iostream>
    2 | using namespace std;
foo.cc:9:1: error: 'cout' was not declared in this scope
    9 | cout<<a<<" "<<b<<" "<<c;
      | ^~~~
foo.cc:9:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:11:1: error: 'cout' was not declared in this scope
   11 | cout<<c<<" "<<a<<" "<<b;
      | ^~~~
foo.cc:11:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:13:1: error: 'cout' was not declared in this scope
   13 | cout<<a<<" "<<c<<" "<<b;
      | ^~~~
foo.cc:13:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:16:1: error: 'cout' was not declared in this scope
   16 | cout<<b<<" "<<a<<" "<<c;
      | ^~~~
foo.cc:16:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:18:1: error: 'cout' was not declared in this scope
   18 | cout<<c<<" "<<b<<" "<<a;
      | ^~~~
foo.cc:18:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?
foo.cc:20:1: error: 'cout' was not declared in this scope
   20 | cout<<b<<" "<<c<<" "<<a;
      | ^~~~
foo.cc:20:1: note: 'std::cout' is defined in header '<iostream>'; did you forget to '#include <iostream>'?

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