#include <fstream>
#include <vector>

void DFS(std::vector<std::vector<int>>& graph, std::vector<bool>& visited, int source) {
	visited[source] = true;

	for (auto neighbour: graph[source])
		if (!visited[neighbour])
			DFS(graph, visited, neighbour);
}

int main() {
	std::ifstream fin("dfs.in", std::ifstream::in);
	std::ofstream fout("dfs.out", std::ofstream::out);

	int n, m;	
	fin >> n >> m;
	std::vector<bool> visited(n + 1, false);
	std::vector< std::vector<int> > graph(n + 1);

	for (int i = 0; i < m; i++) {
		int tmp1, tmp2;
		fin >> tmp1 >> tmp2;
		graph[tmp1].push_back(tmp2);
		graph[tmp2].push_back(tmp1);
	}

	int result = 0;
	for (int i = 1; i <= n; i++) 
		if (!visited[i]) {
			DFS(graph, visited, i);
			result++;
		}
	fout << result;
}