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

using namespace std;

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

vector<int> Graph[100005];
vector<bool> is;

int n, m;

void dfs(int nod)
{
    is[nod] = true;
    for (const auto& val : Graph[nod])
        if (!is[val])
            dfs(val);
}

int main()
{
    int x, y;
    f >> n >> m;
    is = vector<bool> (n);
    while (m--)
    {
        f >> x >> y;
        Graph[x].push_back(y);
        Graph[y].push_back(x);
    }
    int nr = 0;
    for (int i = 1; i <= n; i++)
        if (!is[i])
        {
            dfs(i);
            nr++;
        }
    g << nr;
}