//
//  main.cpp
//  DFS
//
//  Created by Mara Dascalu on 07/10/2021.
//

#include <iostream>

using namespace std;

bool graf[100005][100005], viz[100005];
int n, m, ctr, s, f;

void DFS (int nod)
{
    viz[nod] = 1;
    for (int i = 1; i <= n; i++)
        if (!viz[i] && graf[nod][i]) DFS(i);
}

int main(int argc, const char * argv[]) {
    cout<<" ";
    cin>>n>>m;
    for (int i = 1 ; i <= m; i++)
    {
        cin>>s>>f;
        graf[s][f] = graf[f][s] = 1;
    }
    
    for (int i = 1; i<= n; i++)
        if (!viz[i])
        {
            ctr++;
            DFS(i);
        }
    cout<<ctr;
}