#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <string>

using namespace std;

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

vector<int>v1[100005];
int vf[100005],conex=0;

void dfs(int x){
    vf[x] = 1;
    for(int i=0; i<v1[x].size(); i++){
        if(vf[v1[x][i]] == 0){
            vf[v1[x][i]] = 1;
            dfs(v1[x][i]);
        }
    }

}

int main()
{
    int n,m,a,b;
    fin>>n>>m;
    for(int i=0; i<m; i++){
        fin>>a>>b;
        v1[a].push_back(b);
        v1[b].push_back(a);
    }

    for(int i=1; i<=n; i++){
        if(vf[i]==0){
            dfs(i);
            conex++;
        }

    }
    fout<<conex;
    return 0;
}