#include <fstream>
#include <vector>
using namespace std;

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

int nrn, nrm, nri, cnt, nri2;

vector <int> vec[100005];
bool flag[100005];

void dfs(int nrk){
    flag[nrk] = true;
    for(int &index: vec[nrk])
        if(!flag[index])
            dfs(index);
}

int main()
{
    fin >> nrn >> nrm;
    for(int index = 0; index < nrm; index++){
        fin >> nri;
        fin >> nri2;
        vec[nri].push_back(nri2);
        vec[nri2].push_back(nri);
    }
    for(int index = 1; index <= nrn; index++){
        if(!flag[index]) {
            dfs(index);
            cnt++;
        }
    }
    fout << cnt << '\n';
    return 0;
}