#include <bits/stdc++.h>
#include <fstream>

using namespace std;

int const N_max = 1e5;

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

vector <int> adiacenta[ 1 + N_max];

int vizitat[ N_max];

void DFS( int nod)
{
    vizitat[nod] = 1;
    for ( int  vec : adiacenta[nod])
        if (vizitat[vec] == 0)
        {
            DFS(vec);
        }
}

int main()
{
    int n , m;
    in >> n >> m;
    for ( int i = 1; i <= m; i++ )
    {
        int x , y;
        in >> x >> y;
        adiacenta[x].push_back(y); /// x-> y
        adiacenta[y].push_back(x); /// y -> x
    }
    int nr_c = 0;
    for (int i = 1; i <= n; i++)
        if (vizitat[i] == 0)
        {
            nr_c++;
            DFS (i);
        }
    out << nr_c;
    return 0;
}