#include <bits/stdc++.h>

using namespace std;

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

const int NMAX = 1e5 + 7;

vector<vector<int>> v(NMAX);
vector<bool> ok(NMAX);
int ans;

void dfs(int node)
{
    ok[node] = true;
    for (int i : v[node])
    {
        if (ok[i] == false)
        {
            dfs(i);
        }
    }
}

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

    for (int i = 0; i < m; ++i)
    {
        int a, b;
        fin >> a >> b;
        v[a].push_back(b);
        v[b].push_back(a);
    }

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

    fout << ans;


    return 0;
}