#include <fstream>

#include <vector>
using namespace std;

ifstream fin ("dfs.in");
ofstream fout ("dfs.out");
 
 
vector <int> A[100010];
 
 
 
int v[100010], i, nr , n , m, x, y;
 
 
 
void dfs (int nod)
 {
 	
 	
    v[nod]=1;
    for (int i=0;i<A[nod].size();i++)
        if (v[A[nod][i]]==0)
            dfs(A[nod][i]);
}
 
 
 
int main ()
 {
 
    fin>>n>>m;
    
	
	for (i=1;i<=m;i++) 
	
	{
        fin>>x>>y;
        A[x].push_back(y);
        A[y].push_back(x);
    }
 
    for (i=1;i<=n;i++)
        
		if (v[i]==0) 
		{
            nr++;
            dfs(i);
        }
 
    fout<<nr<<"\n";
 
    return 0;
}