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

using namespace std; 

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

int n, m;
vector < int > L[100005];
bool viz[100005];

void citire()
{
    int x, y;
    fin >> n >> m;
    for(int i = 1; i <= m; i++)
    {
        fin >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }
}

void DFS(int nod)
{
    int nnod;
    viz[nod] = 1;
    for(int i = 0; i < L[nod].size(); i++)
    {
        nnod = L[nod][i];
        if(viz[nnod] == 0)
        {
            DFS(nnod);
        }
    }
}

void solve()
{
    int cont = 0;
    for(int i = 1; i <= n; i++)
    {
        if(viz[i] == 0)
        {
            cont++;
            DFS(i);
        }
    }
    fout << cont;
}

int main()
{ 
    citire();
    solve();
    return 0;
}