#include <iostream>
#include <fstream>
#include <vector>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector < int > v[100001];

int n, m, nr, viz[100001];

void citire()
{
    fin >> n >> m;
    for(int i=1; i<=m; i++)
    {
        int nod1, nod2;
        fin >> nod1 >> nod2;
        v[nod1].push_back(nod2);
        v[nod2].push_back(nod1);
    }
}

void dfs(int x)
{
    viz[x] = 1;
    for(vector< int > ::iterator it=v[x].begin(); it!=v[x].end(); it++)
        if(viz[*it] != 1)
            dfs(*it);
}

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