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