#include<cstdio>
#include<vector>
#include<queue>
using namespace std;
int j,nr,m,x,y,s,i,n,b[100002];
vector < int > h[100002];
void df(int x)
{
	int i;
	b[x]=1;
	for(i=0;i<h[x].size();i++)
		if(b[h[x][i]]==0) df(h[x][i]);
}
int main()
{
freopen("dfs.in","r",stdin);
freopen("dfs.out","w",stdout);
scanf("%d",&n);
scanf("%d",&m);
for(i=1;i<=m;i++)
{
	scanf("%d",&x);
	scanf("%d",&y);
	h[x].push_back(y);
	h[y].push_back(x);
}
for(j=1;j<=n;j++)
	if(b[j]==0)
	{
		df(j);
		nr++;
	}
printf("%d\n",nr);
return 0;
}