#include <fstream>
#include <vector>

using namespace std;


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


const int N = 1e5;
int n, m, cc;
bool viz[N+1];
vector < vector <int> > v;


void dfs(int nod)
{
    viz[nod] = 1;
    for (int i = 0; i < v[nod].size(); i++)
    {
        int vec = v[nod][i];
        if (!viz[vec])
            dfs(vec);
    }
}


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

    v.resize(n+1);

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


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


    fout << cc;


    return 0;
}