#include <bits/stdc++.h>
#define input "dfs.in"
#define output "dfs.out"

using namespace std;

const int nMax = 1e5 + 5;

int n, m, ans;
bool viz[nMax];
vector <int> a[nMax];

void dfs(int x)
{
    viz[x] = true;
    for (auto i : a[x])
        if (viz[i] == false)
            dfs(i);
}

main()
{
    ifstream cin(input);
    ofstream cout(output);
    cin >> n >> m;
    for (; m; --m)
    {
        int x, y;
        cin >> x >> y;
        a[x].emplace_back(y);
        a[y].emplace_back(x);
    }

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

    cout << ans;
}