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



int vf[400001], urm[400001], lst[100001];
int nr;
bool visited[100001];



void add(int x, int y) {
    vf[++nr] = y;
    urm[nr] = lst[x];
    lst[x] = nr;
}

void dfs(int x) {
    visited[x] = true;
    int y;
    for (int p = lst[x]; p != 0; p = urm[p]) {
        y = vf[p];
        if (visited[y] == false) {
            dfs(y);
        }
    }
}

int main() {
    FILE *fin, *fout;
    int n, m, comp;
    fin = fopen("dfs.in", "r");
    fscanf(fin, "%d%d", &n, &m);
    for (int i = 0; i < m; i++) {
        int a, b;
        fscanf(fin, "%d%d", &a, &b);
        add(a, b);
        add(b, a);
    }
    fclose(fin);

    comp = 0;
    for (int i = 1; i <= n; i++) {
        if (visited[i] == false) {
            dfs(i);
            comp++;
        }

    }


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

}