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

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

vector <int> G[100005];
int n, m;
int vizitat[100005];
int cc = 0;

void read()
{
    in >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        int x, y;
        in >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
}

void dfs(int nod)
{
    vizitat[nod] = 1;
    for(int vecin: G[nod])
    {
        if(!vizitat[vecin])
        {
            dfs(vecin);
        }
    }
}

int main()
{
    read();
    for(int i = 1; i <= n; i++)
    {
        if(!vizitat[i])
        {
            dfs(i);
            cc++;
        }
    }
    out << cc;
}