#include <iostream>
#include <fstream>
#include <vector>
#include <stack>
#include <bitset>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

const int NMAX = 100'001;

int N, M;
vector < int > G[NMAX];
bitset < NMAX > vis;

void dfs(const int& node) {

    vis[node] = 1;

    for(const int& neighbor : G[node])
        if(!vis[neighbor])
            dfs(neighbor);
}

int main() {

    f >> N >> M;

    for(int i = 1;i <= M;++i) {
        int x, y;
        f >> x >> y;

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

    int cnt{};
    for(int i = 1;i <= N;++i) {
        if(!vis[i]) {
            dfs(i);
            cnt++;
        }
    }

    g << cnt;

    return 0;
}