#include <bits/stdc++.h>
using namespace std;

const int Nmax = 100005;

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

vector < int > L[Nmax];
int cc[Nmax];
int N, M;
bool viz[Nmax];
int nrcc;

void Read()
{
    ifstream fin("dfs.in");
    fin >> N >> M;
    int x, y;
    while(M--)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}

void DFS(int k)
{
    viz[k] = true;
    for (auto i : L[k])
        if(!viz[i])
            DFS(i);
}

int main()
{
    Read();
    for (int i = 1; i <= N; i++)
        if(!viz[i])
        {
            DFS(i);
            nrcc++;
        }
    fout << nrcc << "\n";
    fout.close();
    return 0;
}