Path Existence

Determine whether there exists a path between two nodes in an undirected graph. The graph will be described by an integer N (the number of nodes) followed by M pairs of integers representing edges. The last line of input will consist of two integers representing the starting and ending nodes. For example: 4 0 1 1 2 2 3 0 3 This indicates there are 4 nodes, edges between 0-1, 1-2, and 2-3, and we want to find a path from node 0 to node 3. Output 'YES' if a path exists, otherwise 'NO'.