Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 2.20×10^6 N , one at an angle 11.0 ∘ west of north, and the other at an angle 11.0 ∘ east of north, as they pull the tanker a distance 0.660 km toward the north. What is the total work done by the two tugboats on the supertankers?