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

using namespace std;

#define MAXN 100010

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

vector<int> G[MAXN];

int viz[MAXN], n, m, nr, x, y;

void dfs(int nod) {
    viz[nod] = 1;

    for (auto it:G[nod]) {
        if (!viz[it]) {
            dfs(it);
        }
    }
}

int main()
{
    f >> n >> m;
    while (m--) {
        f >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for (int i = 1; i <= n; ++i) {
        if (!viz[i]) {
            dfs(i);
            ++nr;
        }
    }

    g << nr;

    return 0;
}