#include <iostream>
#include <vector>
#include <cstdio>
using namespace std;

vector <int> v[1000009];
int viz[100009];

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

int main(){
	freopen("dfs.in","r",stdin);
	freopen("dfs.out","w",stdout);
	int n,m,x,y;
	cin>>n>>m;
	for(int i=1;i<=m;i++){
		cin>>x>>y;
		v[x].push_back(y);
		v[y].push_back(x);
	}
	
	int comp=0;
	for(int i=1;i<=n;i++){
		if(viz[i])continue;
		else{
			comp++;
			dfs(i);
		}
	}
	cout<<comp;
}