#include <iostream>
#include <fstream>
#include <vector>
#define MAX 200002
using namespace std;
int n,m,a,b,cnt,viz[MAX];
vector<int> v[MAX];

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

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

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