#include <bits/stdc++.h>
using namespace std;

char e = '\n';
int n,m,x,y,k,viz[100005];
vector<int>v[100005];

void dfs(int nod){
	viz [nod] = 1;
	for (int i = 0;i<(int)v[nod].size();i++)
		if (! viz[v[nod][i]]) dfs (v[nod][i]);
}

int main(){
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	cin >> n >> m;
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	for(int i=1;i<=n;i++){
		if(!viz[i]){
			k++;
			dfs(i);
		}
	}
	cout << k << e;
	return 0;
}