#include<fstream>
#include<vector>
#define dmax 100003
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
bool viz[dmax];
int n,m,cc;
vector<int>dr[dmax];
void dfs(int k)
{	vector<int>::iterator p;
	for(p=dr[k].begin();p<dr[k].end();p++)
		if(viz[*p]==0)
		{	viz[*p]=1;
			dfs(*p);
		}	
}	
int main()
{	int i,x,y,j;
	in>>n>>m;
	for(i=1;i<=m;i++)
	{	in>>x>>y;
		dr[x].push_back(y);
		dr[y].push_back(x);
	}
	in.close();
	for(i=1;i<=n;i++)
	{	if(viz[i]==0)
		{	cc++;
			dfs(i);
		}
	}	
	out<<cc;
	out.close();
	return 0;
}