#include <bits/stdc++.h>
#define MAXN 100010
using namespace std;

bool V[MAXN];
vector <int> A[MAXN];

void dfs(int node){
	V[node]=1;
	for(int i=0;i<A[node].size();i++){
		if(!V[A[node][i]])dfs(A[node][i]);
	}
}

int main(){
	ifstream cin("dfs.in");
	ofstream cout("dfs.out");
	int n,m,c=0;
	cin>>n>>m;
	for(int i=0;i<m;i++){
		int a,b;
		cin>>a>>b;
		A[a].push_back(b);
		A[b].push_back(a);
	}
	for(int i=1;i<=n;i++){
		if(!V[i]){
			c++;
			dfs(i);
		}
	}
	cout<<c;
}