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

using namespace std;

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

const int NMAX=100005;

int n,m,viz[NMAX],kon;
vector<int> v[NMAX];

void DFS(int nod)
{
    viz[nod] = 1;
    for (auto j : v[nod])
        if (!viz[j])
            DFS(j);
}

int main()
{
    int i;
    fin>>n>>m;
    for (i=1;i<=m;i++)
    {
        int x, y;
        fin>>x>>y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (i=1;i<=n;i++)
        if (!viz[i])
        {
            kon++;
            DFS(i);
        }
    fout<<kon<<"\n";
    return 0;
}