#include<cstdio>
#include<vector>
#define N 100001
using namespace std;
vector<int> v[N];
int n,m,cnt,viz[N];
void dfs( int s)
{
	viz[s]=1;
	for (int i=0; i<v[s].size(); i++)
		if (!viz[v[s][i]])
			dfs (v[s][i]);
}
int main()
{
	freopen ("dfs.in", "r", stdin);
	freopen ("dfs.out", "w", stdout);
	int x,y;
	scanf ("%d %d", &n, &m);
	for (int k=1; k<=m; k++) 
	{
		scanf ("%d %d", &x, &y);
		v[x].push_back(y);
		v[y].push_back(x);
		
	}
	for (int k=1; k<=n; k++)
	{
		if (viz[k]==0) 
		{
			dfs(k);
			cnt++;
		}
	}
	printf ("%d", cnt);
	return 0;
}