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

using namespace std;

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

const int N = 1e5;
bitset<N + 1> viz;
vector<int> a[N + 1];

void dfs(int x)
{
    viz[x] = 1;
    for (auto y : a[x])
    {
        if (!viz[y])
        {
            dfs(y);
        }
    }
}

int main()
{
    int n, m, nc = 0;
    in >> n >> m;

    for (int i = 0; i < m; i++)
    {
        int x, y;
        in >> x >> y;
        a[x].push_back(y);
        a[y].push_back(x);
    }

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

    out << nc;

    in.close();
    out.close();

    return 0;
}