#include<iostream>
#include<vector>
#include<fstream>
using namespace std;
const int NMAX = 10e5;
vector<int>G[NMAX];
int vis[NMAX + 1];

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

void DFS(int x)
{
    // cout << x << " ";
    vis[x] = 1;
    for (auto next : G[x])
    {
        if (!vis[next])
            DFS(next);
    }
}

int main()
{
    int n, m;
    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);
    }

    int cc = 0;

    for (int i = 1; i <= n; i++)
    {
        if (!vis[i])
        {
            cc++;
            DFS(i);
        }
    }
    out << cc;
    return 0;
}