#include <fstream>
#include <vector>
#define NMAX 100005

using namespace std;

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

int i, n, m, x, y, ans = 0;
bool used[NMAX];
vector < int > v[NMAX];

void DFS(int node)
{
    used[node] = 1;

    for (auto & it : v[node])
        if (!used[it])
            DFS(it);
}

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

    for (i = 1; i <= m; ++ i)
    {
        f >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (i = 1; i <= n; ++ i)
        if (!used[i])
    {
        ans ++;
        DFS(i);
    }

    g << ans << '\n';
    return 0;
}