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

using namespace std;

const int MAXN = 100000;
int n,m,nr;
vector<int> G[MAXN + 1];
bool vis[MAXN + 1];

void dfs(int node) {
    vis[node] = true;
    for (int vecin : G[node]) {
        if (!vis[vecin])
            dfs(vecin);
    }
}


int main()
{
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");

    fin>>n>>m;

    for (int i = 0; i < m; i++) {
        int x, y;
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout<<nr;
    return 0;
}