Time Limit: 100005000 MS (Java/Others)    Memory Limit: 6553565535 K (Java/Others)
Total Submission(s): 3532    Accepted Submission(s): 813

Problem Description
   N planets are connected by M bidirectional channels that allow instant transportation. It's always possible to travel between any two planets through these channels. If we can isolate some planets from others by breaking only one channel , the channel is called a bridge of the transportation system. People don't like to be isolated. So they ask what's the minimal number of bridges they can have if they decide to build a new channel. Note that there could be more than one channel between two planets.