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

using namespace std;

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

#define limn 100010
int n,m;
vector <int> G[limn];
int viz[limn], rez;

void dfs(int nod)
{
    viz[nod]=1;
    for (auto it:G[nod])
        if (!viz[it])   dfs(it);
}

int main()
{
    int x,y;
    fin>>n>>m;
    while(m--)
    {
        fin>>x>>y;
        G[x].push_back(y);
        G[y].push_back(x);
    }

    for(int i=1; i<=n; i++)
        if(!viz[i])
            dfs(i), rez++;
    fout<<rez;

    fin.close();
    fout.close();
    return 0;
}