#include <stdio.h>
#include <vector>
#define NMax 100005

using namespace std;

int n, m, uz[NMax];
vector<int> v[NMax];

void dfs(int node)
{
	uz[node] = 1;
	for (int i = 0; i < v[node].size(); i++)
		if (!uz[v[node][i]])
			dfs(v[node][i]);
}

int main()
{
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);

	scanf("%d %d", &n, &m);

	while (m--)
	{
		int x, y;
		scanf("%d %d", &x, &y);
		v[x].push_back(y);
		v[y].push_back(x);
	}

	int c = 0;
	for (int i = 1; i <= n; i++)
		if (!uz[i])
		{
			dfs(i);
			c++;
		}

	printf("%d\n", c);

	return 0;
}