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

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

const int MAX = 100005;

vector<int>lista[MAX];

bool viz[MAX];

int n, m;

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

int main()
{
    fin>>n>>m;

    int i;
    int x, y;
    for(i=1; i<=m; i++)
    {
        fin>>x>>y;
        lista[x].push_back(y);
        lista[y].push_back(x);
    }

    int cnt = 0;
    for(i=1; i<=n; i++)
    {
        if(!viz[i])
        {
            cnt++;
            DFS(i);
        }
    }

    fout<<cnt;
    fin.close();
    fout.close();
    return 0;
}