#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>

typedef long long ll;

const ll mod=1e9+7;

const int dx[] = {0, 1, 0, -1};
const int dy[] = {1, 0, -1, 0};
const int nmax=100005;
#define all(x) x.begin(),x.end()
#define allr(x) x.rbegin(),x.rend()
#define rc(x)  return cout<<x<<"\n",0
#define sz(s)  (int) s.size()
#define pb push_back
#define mp make_pair
#define fr first
#define sc second

using namespace std;

ll t;
vector<int>v[nmax];
ll viz[nmax];

void dfs(int e) {
	viz[e]=1;
	for (auto it:v[e]) {
		if (viz[it]==0) {
			dfs(it);
		}
	}
}

int main() {
ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	ll n,m;
	cin >> n >> m;
	for (int i=1; i<=m; i++) {
		ll x,y;
		cin >> x >> y;
		v[y].pb(x);
		v[x].pb(y);
	}
	ll counter=0;
	for (int i=1; i<=n; i++) {
		if (viz[i]==0) {
			dfs(i);
			counter++;
		}
	}
	cout << counter << '\n';

}