Graph: Maximum In/Out Degree Difference

Graph: maximum in/out degree difference

Read a directed graph: vertices 0 … V-1, E directed edges (u v means u → v). For each vertex i, compute its out-degree (edges leaving i) and in-degree (edges entering i), and print the maximum of |out − in| over all vertices.

Complete maxDegreeDiff.

Pitfall (straight from the bug lab): out-degree and in-degree go opposite ways — for u → v, increment u's out-degree and v's in-degree; do not swap them. The answer is the maximum of the absolute difference.

Input

• Line 1: V E.
• Next E lines: u v, a directed edge u → v.

Output

• One line: the maximum of |out − in| over all vertices (0 if empty / no edges).

Example: input 4 3 / 0 1 / 0 2 / 0 3 -> 3 (vertex 0 has out 3, in 0; diff 3 is the largest).