#include <iostream>
#include <fstream>
#include <vector>
#define nmax 100005
using namespace std;

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

vector<int> v[nmax];
int n, m, componente;
bool seen[nmax];

void dfs(int x){
    seen[x]= true;
    for(int i=0; i<v[x].size(); i++)
        if(!seen[v[x][i]])  dfs(v[x][i]);
}

int main(){
    int x, y;
    fin >> n >> m;
    for(int i=1; i<=m; i++){
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for(int i=1; i<=n; i++)
        if(!seen[i])    dfs(i), componente++;
    fout << componente;
    return 0;
}