#include <stdio.h>
#include <stdbool.h>

#define N 100000
#define M 200000
#define NIL (-1)

struct element {
    int varf, poz_urm;
};

typedef struct element element;

element v[M];
int lst[N+1], nr;
bool viz[N+1];

void init_graf(int n) {
    nr = 0;
    for (int i = 1; i <= n; i++) {
        lst[i] = NIL;
        viz[i] = false;
    }
}

void adauga(int x, int y) {
    // il adauga pe y in lista de adiacenta a lui x
    v[nr].varf = y;
    v[nr].poz_urm = lst[x];
    lst[x] = nr++;
}

void dfs(int x) {
    viz[x] = true;
    for (int p = lst[x]; p != NIL; p = v[p].poz_urm) {
        int y = v[p].varf;
        if (!viz[y]) {
            dfs(y);
        }
    }
}

int main(void) {
    FILE *in, *out;
    in = fopen("dfs.in", "r");
    int n, m;
    fscanf(in, "%d %d", &n, &m);
    init_graf(n);
    for (int i = 0; i < m; i++) {
        int x, y;
        fscanf(in, "%d %d", &x, &y);
        adauga(x, y);
        adauga(y, x);
    }
    fclose(in);
    int nr_comp = 0;
    for (int i = 1; i <= n; i++) {
        if (!viz[i]) {
            nr_comp++;
            dfs(i);
        }
    }
    out = fopen("dfs.out", "w");
    fprintf(out, "%d\n", nr_comp);
    fclose(out);
    return 0;
}