#include <iostream>
#include <vector>
#include <cstdio>

using namespace std;

vector<int> v[100000];
int che[100000];
int n,m,i;


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

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