The input consists of a single test case of the following format.
$N \ Q$
$x_1 \ y_1$
$\vdots$
$x_Q \ y_Q$
The first line consists of two integers N and Q (2≤N≤105,1≤Q≤105). The (i+1)-th line consists of two integers x_i and y_i (1≤x_i,y_i≤N,x_i=y_i).