#include <stdio.h>
#include <stack>
#include <vector>

#define NMAX 100001

using namespace std;

vector<int> adjList[NMAX];
bool visited[NMAX];
int n, m, s;

void DFS(int root) {
	visited[root] = true;
	for (int i = 0; i < adjList[root].size(); ++i) {
		if (!visited[adjList[root][i]]) {
			DFS(adjList[root][i]);
		}
	}
}

int main() {
	FILE *in, *out;
	in = fopen("dfs.in", "r");
	out = fopen("dfs.out", "w");
	int a, b;
	fscanf(in, "%d%d", &n, &m);
	for (int i = 0; i < m; ++i) {
		fscanf(in, "%d%d", &a, &b);
		adjList[a].push_back(b);
		adjList[b].push_back(a);
	}
	int count = 0;

	for (int i = 1; i <= n; ++i) {
		if (!visited[i]) {
			++ count;
			DFS(i);
		}
	}
	fprintf(out, "%d\n", count);
}