#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<vector<int>> gf;
vector<int> viz;
int N,M;

void dfs(int vf){
    viz[vf] = 1;
    for(int x : gf[vf]){
        if(viz[x] == 0)
            dfs(x);
    }
}

int main()
{
    fin>>N>>M;
    gf.resize(N+1);
    viz.resize(N+1);
    for(int i=1; i<=M; i++)
    {
        int X,Y;
        fin>>X>>Y;
        gf[X].push_back(Y);
        gf[Y].push_back(X);
    }

    int nr = 0;

    for(int i=1; i<= N; i++)
    {
        if(viz[i] == 0)
            {
                nr++;
                dfs(i);
            }

    }
    fout<<nr;


    return 0;
}