Roads renewal

In Berland, there are $n$ cities connected by $m$ bidirectional roads. Roads cannot connect a city to itself, and each pair of cities is connected by at most one road. It is not guaranteed that from any city, one can reach any other city using only the existing roads.

The mayor of the city, Gadji Ibrahim, decided to make changes to the road system and tasked the Ministry of Transport with carrying out the reform. Now, each road must become one-way, meaning it should only lead in one direction — from one city to another.

To avoid discontent among the residents, the reform must be carried out in such a way that the number of isolated cities is minimized. A city is considered isolated if no road enters it (although roads leaving this city are allowed).

Help Gadji Ibrahim find the minimal number of isolated cities after the reform.

Input

The first line contains two positive integers $n$ and $m(2\le n\le 10^5,1\le m\le 10^5)$ — the number of cities and roads in Berland.

The next $m$ lines describe the roads: the $i$-th road is represented by two distinct integers $x_i$ and $y_i(1\le x_i,y_i\le n,x_i\ne y_i)$, where $x_i$ and $y_i$ are the numbers of the cities connected by the $i$-th road.

It is guaranteed that no more than one road exists between any pair of cities, but it is not guaranteed that from any city, one can reach any other city using only the existing roads.

Output

Print a single number — the minimal number of isolated cities after the reform.

Examples