#include <iostream>
#include <fstream>
#include <vector>

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector<int> v[100001];
bool f[100001];
int n, m, x, y;

void dfs(int nodul) {
    if (!f[nodul]) {
        f[nodul] = 1;
        for (auto i : v[nodul]) dfs(i);
    }
    
}

int main() {
    fin>>n>>m;

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

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

    int k = 0;
    for (int i = 1; i <= n; i++) {
        if (!f[i]) dfs(i), k++;
    }

    fout<<k;

    return 0;
}