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

using namespace std;

vector<int> v[100009];
int che[100009];
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]) {
            continue;}
	    else{
	    	comp++;
	    	dfs(i);
		}
	}
	cout<<comp;
}