#include<stdio.h>
#include<vector>
#define N 200000
using namespace std;
vector <int> a[N];
int n,m,t,nr, tin[N], tout[N];
bool viz[N];
void dfs(int x)
{
	tin[x]=t++;
	viz[x]=true;
	for(int i=0;i<a[x].size();++i)
	{
		int y=a[x][i];
		if(!viz[y])
			dfs(y);
	}
}

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

}