#include <bits/stdc++.h>
#define NMAX 100005

using namespace std;
FILE *in, *out;

int nr_noduri, nr_muchii;

vector<int> muchii[NMAX];
bool parcurs[NMAX];

void read() {
    in = fopen("dfs.in", "r");

    fscanf(in, "%d %d", &nr_noduri, &nr_muchii);
    for(int i = 1; i <= nr_muchii; ++i) {
        int x, y;
        fscanf(in, "%d %d", &x, &y);

        muchii[x].push_back(y);
        muchii[y].push_back(x);
    }
    fclose(in);
}

void DFS(int nod) {
    parcurs[nod] = 1;
    for(int k = 0; k < muchii[nod].size(); ++k) {
        int vecin = muchii[nod][k];
        if(!parcurs[vecin])
            DFS(vecin);
    }
}

int main()
{
    read();

    int comp_conexe = 0;
    for(int i = 1; i <= nr_noduri; ++i) {
        if(!parcurs[i]) {
            ++comp_conexe;
            DFS(i);
        }
    }

    out = fopen("dfs.out", "w");
    fprintf(out, "%d", comp_conexe);
    fclose(out);
    return 0;
}