#include <iostream>
#include <fstream>
#include <vector>
#define nmax 200000
using namespace std;

ifstream in("dfs.in");
ofstream out("dfs.out");

int n,m,a,b,i,con;
vector <int> v[nmax];
int viz[nmax];

void dfs(int x){
    int j;
    
    for (j=0; j<v[x].size(); j++)
        if (!viz[v[x][j]]){
            viz[v[x][j]]=1;
            dfs(v[x][j]);
        }
}

int main(){
    
    in >> n >> m;
    
    for (i=1; i<=m; i++){
        in >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }
    
    for (i=1; i<=n; i++){
        if (!viz[i]){
            con++;
            viz[i]=1;
            dfs(i);
        }
    }
    
    out << con << "\n";
    
    return 0;
}