A helicopter was flying around above Seattle when an electrical malfunction disabled all the navigation and communications equipment. The pilot saw a tall building, flew toward it, circled, drew a handwritten sign saying "Where am I?" and held it in the helicopter's window. People in the tall building drew a large sign, and held it in a windows, "You are in a helicopter". The pilot smiled, waved, looked at his map, determined the course to steer to Seatac airport and landed safely. When his co-pilot asked how the sign had helped, the pilot responded, "I knew that had to be ---??--- building as they gave me a ----????----". Fill in the missing parts of the pilots reply?