#include<fstream>
#include<vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
void DFS(int i,vector<vector<int>>&graph,vector<bool>&visited) {
	visited[i] = true;
	for (int j = 0; j < graph[i].size(); j++)
		if (!visited[graph[i][j]])
			DFS(graph[i][j], graph,visited);
}
int main() {
	int n, m;
	int x, y;
	fin >> n >> m;
	int conex_components = 0;
	vector<vector<int>>graph(n+1);
	vector<bool>visited(n+1);
	for (int i = 1; i <= n; i++)
		visited[i] = false;
	for (int i = 0; i < m; i++) {
		fin >> x >> y;
		graph[x].push_back(y);
		graph[y].push_back(x);
	}
	for (int i = 1; i <= n; i++) {
		if (!visited[i]) {
			conex_components++;
			DFS(i, graph, visited);
		}
	}
	fout << conex_components;
	return 0;
}