#include <iostream>
#include <fstream>
#include <queue>

using namespace std;

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

const int maxN = 1e5 + 5;

vector <int> g[maxN];
bool visit[maxN];

void dfs (int node) {
    visit[node] = true;

    for(int to : g[node])
        if(visit[to] == false)
            dfs(to);
}

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

    for(int i = 1; i <= m; ++i) {
        int u, v; fin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    int ans = 0;
    for(int i = 1; i <= n; ++i)
        if(visit[i] == false) {
            dfs(i);
            ans++;
        }

    fout << ans;

    return 0;
}