Description
Over time, exploration teams will build more communications bases and set them up at each site. However, there's still a problem! Some sites simply cannot be connected at all, no matter how many bases are used.
You must analyze a connectivity network and identify how many distinct (unconnected) components a graph is divided into.
Input Format
The first line contains N, the number of sites being analyzed, and M, the number of connections that will exist when all nodes are in place.
The next M lines each have two values identifying a pair of connected sites.
Constraints
1 ≤ N ≤ 200
1 ≤ M ≤ 10,000
0 ≤ site IDs < N
Output Format
Print the number of indepent site clusters in the input graph.
Example 0
Sample Input
9 10
0 3
0 4
0 5
1 2
1 6
1 8
2 8
3 7
4 7
6 8
Sample Output
2
Explanation
This graph looks like this:
