please use python to solve this question. Show me the code and make sure it us runnable.

thank you

Given a list of airline tickets represented by pairs of departure and arrival airports [from, to],reconstruct the itinerary in order. All of the tickets belong to a man who departs from JFK . Thus, the itinerary must begin with JFK Note: 1. If there are multiple valid itineraries, you should return the itinerary that has the smallest lexical order when read as a single string. For example, the itinerary"JFK","LGA"] has a smaller lexical order than "JFK","LGB" 2. All airports are represented by three capital letters (IATA code). 3. You may assume all tickets form at least one valid itinerary. Example 1: Input: [["MUC", "LHR"], ["JFK", "MUC"], ["SFO", "SJC"], ["LHR", "SFo"]] Output: ["JFK", "MUC", "LHR", "SFo", "SJC" Example 2: Input: [["JFK", "SFO"], ["JFK", "ATL"], ["SFO", "ATL", ["ATL", "JFK", ["ATL", "SFO ]] Output: ["JFK", "ATL", "JFK", "SFO", "ATL", "SFO"] Explanation: Another possible reconstruction is ["JFK", "SFO, "ATL", "JFK", "ATL","SFO"] But it is larger in lexical order