#include <iostream>
#include <fstream>
#include <vector>
#include <bitset>
using namespace std;

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

const int nmax = 1e5+5;
vector <int> g[nmax];
bitset <nmax> viz;

void dfs(int dad)
{
    vector <int> :: iterator son;
    viz[dad]=true;
    for(son=g[dad].begin(); son!=g[dad].end(); son++)
        if(viz[*son]==false) dfs(*son);
}

int main()
{
    ios_base::sync_with_stdio(false);
    int n, m, i, x, y, nr=0;
    fin >> n >> m;
    while(m--)
    {
        fin >> x >> y;
        g[x].push_back(y);
        g[y].push_back(x);
    }
    for(i=1; i<=n; i++)
        if(viz[i]==false)
        {
            dfs(i);
            nr++;
        }
    fout << nr;
    fin.close();
    fout.close();
    return 0;
}