#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
const int NMAX=100005;
vector<int>vec[NMAX];
int n,m,insule=0;
bool vizitat[NMAX];

void dfs(int NOD){
vizitat[NOD]=true;
for(unsigned int i=0;i<vec[NOD].size(); i++){
    int vecin=vec[NOD][i];
    if(!vizitat[vecin])dfs(vecin);
}

}


void citire(){
int i,x,y;
in >> n >> n;
for(i=0;i<m;i++){
    in >> x >> y;
    vec[x].push_back(y);
    vec[y].push_back(x);
}
for(i=1;i<=n;i++){
    if(!vizitat[i]){
        insule++;
        dfs(i);
    }
}
}

int main(){
citire();
out << insule;
return 0;}