#include <fstream>
#include <vector>
#include <bits/stdc++.h>
std::vector<std::vector<int>> graf;
std::bitset<100000>nod_folosit;

std::ifstream input_file("dfs.in");
std::ofstream output_file("dfs.out");



void dfs(int nod) {
    nod_folosit[nod]=1;
    for (int urmator:graf[nod]) {
        if (!nod_folosit[urmator])
            dfs(urmator);
    }
}
//
// void bfs(int nod) {
//
// }

int main() {
    int n,m,x,y,no_componente_conexe=0;
    input_file>>n>>m;

    graf.assign(n+1,std::vector<int>());
    for (int i=1;i<=m;i++) {
        input_file>>x>>y;
        graf[x].push_back(y);
        graf[y].push_back(x);
    }

    for (int i=1;i<=n;i++) {
        if (!nod_folosit[i]) {
            no_componente_conexe++;
            dfs(i);
        }
    }

    output_file<<no_componente_conexe;
    return 0;
}