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

ifstream fin("dfs.in");
ofstream fout("dfs.out");
vector <int> L[100001];
bitset<1000001> viz;
void dfs(int nod)
{
    viz[nod] = 1;
    for (auto it : L[nod])
        if (!viz[it])
            dfs(it);
}
int main()
{
    int n, m;
    fin >> n >> m;
    for (int i = 1; i <= m; i++)
    {
        int x, y;
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
    int cnt = 0;
    for(int i=1; i<=n; i++)
    { 
        if (!viz[i])
            dfs(i), cnt++;
    }
    fout << cnt;
    return 0;
}