#include <fstream>
#include <vector>

using namespace std;


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

const int N = 1e5;
vector <int> a[N+1];
int viz[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;
    return 0;
}