/in/foo.cc: In function 'int main()':
/in/foo.cc:22:25: error: 'cin' was not declared in this scope
     int x1, y1, z1;     cin >> x1 >> y1 >> z1;
                         ^~~
/in/foo.cc:26:5: error: 'cout' was not declared in this scope
     cout << t1.timeconsion() - t2.timeconsion();
     ^~~~