Metro Connectivity

You are given a map of a city's metro system as an undirected graph. Each station is a node and each line connecting two stations is an edge. Write a program to find the shortest path in terms of number of lines taken to get from a starting station to a destination station. You will receive the number of stations, followed by a list of lines as pairs representing the connections between the stations, and finally a pair of stations indicating the start and end. If there is no path, return -1. Input Format: - The first line contains an integer n (number of stations). - The second line contains an integer m (number of connections). - The next m lines contain two integers u and v, representing a connection between stations u and v. - The last line contains two integers s and d, the start station and the destination station. Output Format: - Print the minimum number of lines needed to reach the destination station from the start station, or -1 if no such path exists. Example: Input: 5 4 1 2 1 3 2 4 3 4 1 4 Output: 2