/in/foo.cc:2:7: error: expected nested-name-specifier before 'namepeace'
    2 | using namepeace std;
      |       ^~~~~~~~~
/in/foo.cc: In function 'int main()':
/in/foo.cc:7:9: error: 'cin' was not declared in this scope
    7 |         cin>>a>>b>>c;
      |         ^~~
/in/foo.cc:8:9: error: 'cout' was not declared in this scope
    8 |         cout<<b<<endl;
      |         ^~~~
/in/foo.cc:8:18: error: 'endl' was not declared in this scope
    8 |         cout<<b<<endl;
      |                  ^~~~