To defeat Thanos requires a certain amount of energy (at least 81,000 fighting power), for which you have different avengers with 3 energy levels. Thor, Hulk, Ironman, Starlord, Vision, Dr. Strange, and Wanda have power level 1 (7,000 fighting power). Captain America, Black Panther, Spiderman, Winter Soldier, Iron Machine, Groot, Drax, and Ant Man have energy level 2 (5,000 fighting power). Hawkeye, Black Widow, Rocket, Falcon, and Gamora have an energy level of 3 (4,000 fighting power). If during the fight we use a level 1 hero, the destruction on the ground will be 500 km2; if we use a level 2 hero, it will be 325 km2, and if we use a level 3 hero, it will be 250 km2. Each additional avenger that participates adds to the land's destruction area according to his level. State the problem and explain each stage of the approach.