Trade Unions are common these days in the industries. But the new manager of ByteComp don't like those unions. He wants the division between them. Before he goes on process of division, he wants to find out the number of ways in which he can divide the existing trade union in two parts by kicking out one of the workers. Given N , the number of workers in the company and 'R' , the number connections in the union and R pairs of connections. Find the ways in which the original configuration of union can be divided.

INPUT FORMAT :
The first line of input contains two space seperated integers N and R. The next R lines contains the relation among workers. The workers are numbered from 0 to N-1.

OUPUT FORMAT:
Print the number of ways in which the trade union can be divided into two parts.

CONSTRAINTS:
0 < N < 10000
0 < R < 10000