#include<bits/stdc++.h>
using namespace std;
const int N=100020;
vector <int> mda[N];
bool v[N];
void dfs(int nod){
	v[nod]=1;
	int k=mda[nod].size();
	for(int i=0;i<k;i++)if(!v[mda[nod][i]]){
		dfs(mda[nod][i]);
	}
}
int main(){
	int n, m;
	ifstream f("dfs.in");
	ofstream g("dfs.out");
	f>>n>>m;
	int x, y;
	while(m--){
		f>>x>>y;
		mda[x].push_back(y);
		mda[y].push_back(x);
	}
	int k=0;
	for(int i=1;i<=n;i++)if(!v[i]){
		k++;
		dfs(i);
	}
	g<<k;
	return 0;
}