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

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector<int> lista[100010];
int freq[100010];

void dfs(int start) {
    freq[start] = 1;

    for (int i = 0; i < lista[start].size(); i++)
        if (!freq[lista[start][i]])
            dfs(lista[start][i]);
}

int main() {
    int n, m;
    int x, y;

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

        lista[x].push_back(y);
        lista[y].push_back(x);
    }

    int counter = 0;
    for (int i = 1; i <= n; i++)
        if (!freq[i]) {
            dfs(i);
            counter++;
        }

   fout << counter;

    return 0;
}