#include <algorithm>
#include <cstring>
#include <fstream>
#include <iostream>
#include <vector>
#include <queue>
#include <bitset>

using namespace std;

#define NMAX 100001

bitset<NMAX> visited;
vector<int> v[NMAX];
int n,m;

void dfs(int nod)
{
    visited[nod] = 1;
    for (vector<int>::iterator it = v[nod].begin(); it != v[nod].end(); ++it)
        if (!visited[*it])
            dfs(*it);
}

int main()
{
    fstream fin("dfs.in", fstream::in);
    fin >> n >> m;
    int x, y;
    for (int i = 0; i < m; i++)
    {
        fin >> x >> y;
        --x; --y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    fin.close();
    int sol = 0;
    visited.reset();
    for (int i = 0; i < n; i++)
        if (!visited[i])
        {
            ++sol;
            dfs(i);
        }
    fstream fout("dfs.out", fstream::out);
    fout << sol;
    fout.close();
    return 0;
}