Suppose Andy and Doris want to choose a restaurant for dinner, and they both have a list of favorite restaurants represented by strings. You need to help them find out their common interest with the least list index sum. If there is a choice tie between answers, output all of them with no order requirement. You could assume there always exists an answer. Example 1: Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["Piatti","The Grill at Torrey Pines","Hungry Hunter Steakhouse","Shogun"] Output: ["Shogun"] Explanation: The only restaurant they both like is "Shogun". Example 2: Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["KFC","Shogun","Burger King"] Output: ["Shogun"] Explanation: The restaurant they both like and have the least index sum is "Shogun" with index sum 1 (0+1). Example 3: Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["KFC","Burger King","Tapioca Express","Shogun"] Output: ["KFC","Burger King","Tapioca Express","Shogun"] Example 4: Input: list1 = ["Shogun","Tapioca Express","Burger King","KFC"], list2 = ["KNN","KFC","Burger King","Tapioca Express","Shogun"] Output: ["KFC","Burger King","Tapioca Express","Shogun"] Example 5: Input: list1 = ["KFC"], list2 = ["KFC"] Output: ["KFC"] Constraints: 1 <= list1.length, list2.length <= 1000 1 <= list1[i].length, list2[i].length <= 30 list1[i] and list2[i] consist of spaces ' ' and English letters. All the stings of list1 are unique. All the stings of list2 are unique.