#include <bits/stdc++.h>

using namespace std;

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

int n, m, nr, vf[400001], urm[400001], last[100001];
bitset <100001> viz;

void adauga(int nod, int v){
    vf[++nr] = v;
    urm[nr] = last[nod];
    last[nod] = nr;

}

void dfs(int nod){
    viz[nod] = 1;

    for(int k = last[nod]; k; k = urm[k])
        if(!viz[vf[k]])
            dfs(vf[k]);

}


void citire(){
    fin>>n>>m;
    for(int i, j, k = 1; k<=m; k++)
    {
        fin>>i>>j;
        adauga(i, j);
        adauga(j, i);
    }
}


int main()
{
    citire();
    int nrComp = 0;
    for(int i=1; i<=n; i++)
        if(!viz[i])
        {
            dfs(i);
            nrComp ++;
        }
    fout<<nrComp;

    return 0;
}