foo.cc: In function ‘int main()’:
foo.cc:4:9: error: ‘cin’ was not declared in this scope
    4 |         cin>>a>>b>>c;
      |         ^~~
foo.cc:7:25: error: ‘cout’ was not declared in this scope
    7 |                         cout<<c<<" "<<b<<" "<<a<<endl;
      |                         ^~~~
foo.cc:7:50: error: ‘endl’ was not declared in this scope
    7 |                         cout<<c<<" "<<b<<" "<<a<<endl;
      |                                                  ^~~~
foo.cc:10:33: error: ‘cout’ was not declared in this scope
   10 |                                 cout<<b<<" "<<c<<" "<<a<<endl;
      |                                 ^~~~
foo.cc:10:58: error: ‘endl’ was not declared in this scope
   10 |                                 cout<<b<<" "<<c<<" "<<a<<endl;
      |                                                          ^~~~
foo.cc:12:33: error: ‘cout’ was not declared in this scope
   12 |                                 cout<<b<<" "<<a<<" "<<c<<endl;
      |                                 ^~~~
foo.cc:12:58: error: ‘endl’ was not declared in this scope
   12 |                                 cout<<b<<" "<<a<<" "<<c<<endl;
      |                                                          ^~~~
foo.cc:15:21: error: ‘cout’ was not declared in this scope
   15 |                     cout<<c<<" "<<a<<" "<<b<<endl;
      |                     ^~~~
foo.cc:15:46: error: ‘endl’ was not declared in this scope
   15 |                     cout<<c<<" "<<a<<" "<<b<<endl;
      |                                              ^~~~
foo.cc:18:21: error: ‘cout’ was not declared in this scope
   18 |                     cout<<a<<" "<<c<<" "<<b<<endl;
      |                     ^~~~
foo.cc:18:46: error: ‘endl’ was not declared in this scope
   18 |                     cout<<a<<" "<<c<<" "<<b<<endl;
      |                                              ^~~~
foo.cc:20:21: error: ‘cout’ was not declared in this scope
   20 |                     cout<<a<<" "<<b<<" "<<c<<endl;
      |                     ^~~~
foo.cc:20:46: error: ‘endl’ was not declared in this scope
   20 |                     cout<<a<<" "<<b<<" "<<c<<endl;
      |                                              ^~~~