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

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

int n, m, cnt;
vector<bool> viz;
vector<vector<int>> G;

void dfs(int start) {
    viz[start] = true;
    for(int x : G[start]) {
        if(!viz[x]) {
            dfs(x);
        }
    }
}

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

    G.resize(n + 1);
    viz.resize(n + 1);

    for(int x, y; m--;) {
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

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

    fout << cnt;
}