You are given a graph with N nodes and M directed edges. Find $C - D$.

Where,

C Sum of number of nodes in all Strongly Connected Components with odd number of nodes.

D Sum of number of nodes in all Strongly Connected Components with even number of nodes.

Input:

First line contains 2 integers, N and M, denoting the number of nodes and the number of edges. Next M lines contain 2 integers A and B, meaning that there is a directed edge from A to B.

Output:

Output the number $C - D$.

Constraints:

$1 \le N, M \le 15$

$1 \le A, B \le N$