#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> a[100005];
int n, m;
bitset <100005> viz;

void Dfs(int x)
{
    viz[x] = 1;
    for (auto w : a[x])
        if (viz[w] == 0)
            Dfs(w);
}
int main()
{
    int i, j, sol = 0;
    fin >> n >> m;
    while (m--)
    {
        fin >> i >> j;
        a[i].push_back(j);
        a[j].push_back(i);
    }

    for (i = 1; i <= n; i++)
        if (viz[i] == 0)
        {
            Dfs(i);
            sol++;
        }

    fout << sol << "\n";



    return 0;
}