#include <fstream>
#include <cstring>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, x, y, sol, fr[100010];
vector < int > V[100010];

inline void DFS(int nod)
{
    fr[nod] = 1;
    for (int j=0; j<V[nod].size(); j++) if (!fr[V[nod][j]]) DFS(V[nod][j]);
}

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

    for (int i=1; i<=n; i++)
    {
        if (!fr[i])
        {
            sol++;
            DFS(i);
        }
    }

    fout << sol << '\n';
    fout.close();
    return 0;
}