#include <fstream>
#include <vector>

#define N 100005

using namespace std;

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

vector <int> muchii[N];
int viz[N], n, m, cate;

void DFS(int nod)
{
    int i;
    viz[nod] = 1;

    for( auto i: muchii[nod])
        if(viz[i] == 0)
            DFS(i);
}

int main()
{
    int i;

    f >> n >> m;

    for(i = 1; i <= m; i++)
    {
        int a, b;
        f >> a >> b;

        muchii[a].push_back(b);

        muchii[b].push_back(a);
    }

    for (int i = 1; i <= n; i++)
        if (viz[i] == 0)
        {
            cate++;
            DFS(i);
        }

    g << cate << "\n";
}