#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define MAX 100010
vector < int > G[MAX];
int viz[MAX];
void dfs(int nod)
{
    viz[nod]=1;
    for ( int i = 0; i<G[nod].size(); i++)
    {
        if(!viz[G[nod][i]])
            dfs(G[nod][i]);
    }
}

int main()
{
    int n, m, k=0,a,b;
    fin >> n >> m;
    while (m--) {
        fin >> a >> b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    for( int i = 1; i<=n; i++)
    {
        if(!viz[i])
            dfs(i),k++;
    }
    fout << k << "\n";


    return 0;
}