Processing math: 100%
Connected component - MarisaOJ: Marisa Online Judge

Connected component

Time limit: 1000 ms
Memory limit: 256 MB

Given a undirected graph of n vertices and m edges. Count the number of connected components in this graph.

Input

  • The first line contains 2 integers n,m.
  • The next m lines, each line contains 2 integers u,v, there is an edge between those vertices.

Output

  • Print the number of connect components.

Constraints

  • 1≤n,m≤105.
  • 1≤u,v≤105.

Example

Input:

5 4
1 2
1 3
2 3
4 5

Output:

2