#include <iostream>
#include <fstream>
#include <vector>
using namespace std;

#define MAX 100005
ifstream fin("dfs.in");
ofstream fout("dfs.out");

vector < int > v[MAX];
bool viz[MAX];
void dfs(int nod)
{
    viz[nod] = true;
    for(int i = 0; i<v[nod].size(); i++)
        if(!viz[v[nod][i]])
            dfs(v[nod][i]);
}
int main()
{
    int n, m, x, y, k = 0;
    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(!viz[i])
        {
            dfs(i);
            k++;
        }
    }
    fout << k << "\n";
    return 0;
}