#include <bits/stdc++.h>

using namespace std;

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

queue<int>q;

vector<int>graph[100005];
bool viz[100005];
int n, m, a, b;

void parcurgere(int ind)
{
    viz[ind]=1;
    for (auto &v:graph[ind])
    {
        if (!viz[v])
        {
            parcurgere(v);
        }
    }
}

int main()
{
    f >> n >> m;
    for (int i=1; i<=m; ++i)
    {
        f >> a >> b;
        graph[a].push_back(b);
        graph[b].push_back(a);
    }
    int nr=0;
    for (int i=1; i<=n; ++i)
    {
        if (!viz[i])
        {
            parcurgere(i);
            nr++;
        }
    }
    g << nr;
    return 0;
}