#include <fstream>
#include <cstring>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n, m, a, b, nrc, 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()
{
    in >> n >> m;
    for (int i=1; i<=m; i++)
    {
        in >> a >> b;
        V[a].push_back(b);
        V[b].push_back(a);
    }
 
    for (int i=1; i<=n; i++)
    {
        if (!fr[i]) { nrc++; DFS(i);}
    }
 
    out << nrc << '\n';
    out.close();
    return 0;
}