Road Reform#2073
In the city of Vinnytsia, as in most Ukrainian cities, there is a network of roads where traffic flows in both directions. This network is fully connected, meaning you can travel between any two points in the city.
Recently, traffic congestion has become a major issue on the city's roads. To alleviate this, the mayor has decided to convert some roads to one-way traffic to increase capacity and reduce jams. Your task is to determine the maximum number of roads that can be converted to one-way traffic without losing the network's connectivity.
The input consists of two integers: — the number of intersections in the city, and — the number of roads (1 \leq N \leq 20000, 1 \leq M \leq 200000). Following this, lines are provided, each containing two integers representing the intersections connected by a road. No pair of intersections is connected by more than one road.
The output should be a single integer , representing the maximum number of roads that can be converted to one-way traffic while maintaining the network's connectivity.
Example 1