#include<cstdio>
#include<vector>

using namespace std;

int n,m,nr;
vector<int> matei[100010], cimp [100010];
bool marc[100010];
void citire();
void dfs(int);

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

void dfs(int nod)
{
	marc[nod]=1;
	cimp[nr].push_back(nod);
	for(size_t i=0; i<matei[nod].size();++i)
		if(!marc[matei[nod][i]])
		{
			dfs(matei[nod][i]);
		}
}