#include <iostream>
#include <fstream>

using namespace std;

int n, m, x, y, nr_comp;
int head[100005];
int to[400005];
int nxt[400005];
int viz[100005];
int edge_cnt;

void adauga_muchie(int u, int v) {
    edge_cnt++;
    to[edge_cnt] = v;
    nxt[edge_cnt] = head[u];
    head[u] = edge_cnt;
}

void dfs(int nod) {
    viz[nod] = 1;
    for (int i = head[nod]; i != 0; i = nxt[i]) {
        int vecin = to[i];
        if (viz[vecin] == 0) {
            dfs(vecin);
        }
    }
}

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

    fin >> n >> m;
    
    for (int i = 1; i <= m; i++) {
        fin >> x >> y;
        adauga_muchie(x, y);
        adauga_muchie(y, x);
    }

    for (int i = 1; i <= n; i++) {
        if (viz[i] == 0) {
            nr_comp++;
            dfs(i);
        }
    }

    fout << nr_comp << "\n";

    return 0;
}