#include <vector>
#include <fstream>

using namespace std;

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

vector <int> V[100005];
bool viz[100005];
int m,n,x,y,k;

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

int main()
{

    in >> n >> m;

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

    for (int i=1; i<=n; i++)
    {
        if (!viz[i])
            dfs(i), k++;
    }
    out << k;
    return 0;
}