#include<cstdio>
#include<algorithm>
#include<vector>
using namespace std;

const int maxN=100005;
vector<int> G[maxN];
int m,n,nr,viz[maxN];

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

int main()
{
	citire();
	nr=0;
	for(int i=1;i<=n;++i)
		if(!viz[i])
		{
			nr++;
			dfs(i);
		}
	printf("%d\n",nr);
	return 0;
}