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

using namespace std;

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

vector <int> v[100005];
int use[100005];

void dfs(int nod)
{
    use[nod] = 1;
    for (int i = 0; i < v[nod].size(); i++)
        if (!use[v[nod][i]])
            dfs(v[nod][i]);
}

int main()
{
    int n, m, x, y, nr = 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 (!use[i])
        {
            nr++;
            dfs(i);
        }
    fout << nr << '\n';
    return 0;
}