#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <queue>
#include <bitset>
#define NMAX 100008
#define inf 0x3f3f3f3f

using namespace std;

int n, m;
vector<int> v[NMAX];
bitset<NMAX> viz;

void citire()
{
    int x, y;
    scanf("%d %d", &n, &m);
    for (int i=0; i<m; i++){
        scanf("%d %d", &x, &y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

}

void dfs(int i){

    viz[i] = 1;
    for (vector<int>::iterator it = v[i].begin(); it != v[i].end(); it++){
        if (!viz[*it]){
            dfs(*it);
        }
    }

}

int main()
{
    freopen("dfs.in", "r", stdin);
    freopen("dfs.out", "w", stdout);
    citire();
    int nrComp = 0;
    for (int i=1; i<=n; i++){
        if (!viz[i]){
            dfs(i);
            nrComp++;
        }
    }
    printf("%d\n", nrComp);

    return 0;
}