#include <bits/stdc++.h>
#define pb push_back
#define mp make_pair
using namespace std;

const string FILENAME = "bfs";

ifstream fin(FILENAME + ".in");
ofstream fout(FILENAME + ".out");

int n, m, ans = 0;
bool viz[100001];
vector<int> adj[100001];

void DFS(int nod)
{
    viz[nod] = 1;
    for(int i : adj[nod])
        if(!viz[i])
            DFS(i);
}

int main()
{
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        adj[x].pb(y);
        adj[y].pb(x);
    }
    for(int i = 1; i <= n; i++)
        if(!viz[i])
        {
            ans++;
            DFS(i);
        }
    fout << ans << "\n";
    fin.close();
    fout.close();
    return 0;
}