#include<cstdio>
#include<vector>
#define DN 100100
using namespace std;
vector<int> gr[DN];
int n, m, cont, viz[DN];
void  dfs(int x)
{
	viz[x]=1;
	int stop=gr[x].size();
	for(int i=0; i<stop; i++)
	{
		if(!viz[gr[x][i]])
			dfs(gr[x][i]);
	}
}
int main()
{
	freopen("dfs.in", "r", stdin);
	freopen("dfs.out", "w", stdout);
	scanf("%d%d", &n, &m);
	for(int i=1; i<=m; i++)
	{
		int a, b;
		scanf("%d%d", &a, &b);
		gr[a].push_back(b), gr[b].push_back(a);
	}
	for(int i=1; i<=n; i++)
	{
		if(!viz[i])
			cont++, dfs(i);
	}
	printf("%d\n", cont);
	fclose(stdin);
	fclose(stdout);
}