#include <iostream>
#include <vector>
#include <fstream>

using namespace std;

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

void dfs(int nod,vector <vector<int>> &Graf,vector <int> &viz)
{
    viz[nod]=1;
    for(auto i: Graf[nod])
    {
        if(viz[i]==0)
            dfs(i,Graf,viz);
    }
}
int main()
{
    int n,m;
    in>>n>>m;
    vector <vector<int>> Graf(n+1);
    vector <int>viz(n+1,0);
    for(int i=0;i<m;i++)
    {
        int x,y;
        in>>x>>y;
        Graf[x].push_back(y);
        Graf[y].push_back(x);
    }
    int nr_comp=0;
    for (int i=1;i<=n;i++)
    {
		if (viz[i] == 0)
        {
			dfs(i,Graf, viz);
			nr_comp++;
		}
	}

    out<<nr_comp;
    return 0;
}