#include <stdio.h>
#include <vector>
using namespace std;
#define Max 100001

vector<int>g[Max];
bool viz[Max];

void dfs(int x)
{
	int y;
	viz[x]=1;
	for(int i=0;i<g[x].size();i++)
	{
		y=g[x][i];
		if(!viz[y])dfs(y);
	}
}

int main()
{
	int n,m,x,y;
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
		scanf("%d %d",&n,&m);
		for(int i=1;i<=m;i++)
		{
			scanf("%d %d",&x,&y);
			g[x].push_back(y);
			g[y].push_back(x);
		}
		m=0;
		for(int i=1;i<=n;i++)
			if(!viz[i])
			{
				m++;
				dfs(i);
			}
		printf("%d\n",m);

	return 0;
}