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

using namespace std;

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

const int NLIM=100000;
vector<int> adiacenta[NLIM];
bool use[NLIM];
int n,m,conexe=0;

void citire() {
fin>>n>>m;
for(int i=0;i<m;i++) {
    int x,y;
    fin>>x>>y;
    adiacenta[x].push_back(y);
    adiacenta[y].push_back(x);
}
}
void dfs(int nod) {
use[nod]=1;
for(unsigned int i=0;i<adiacenta[nod].size();i++) {
    int vecin=adiacenta[nod][i];
    if(use[vecin]==0) dfs(vecin);
}
}


int main() {
citire();
for(int i=0;i<n;i++) {
    if(use[i]==0) {
        conexe++;
        dfs(i);
    }

}
fout<<conexe;
return 0;
}