#include <bits/stdc++.h>
using namespace std;

bool f[100005];

vector<int>stk[100005];

void dfs (int q){
    f[q] = 1;
    for (auto v:stk[q]) {
        if (f[v] == 0) {
            dfs(v); } } }

int main() {
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    int n, m, x, y, ans = 0;
    scanf ("%d %d", &n, &m);
    for (int i = 1; i <= m; i++) {
        scanf("%d %d", &x, &y);
        stk[x].push_back(y);
        stk[y].push_back(x); }
    for (int  i = 1; i <= n; i++) {
        if (f[i] == 0) {
            dfs(i);
            ans++; } }
    printf("%d\n", ans);
    return 0; }