#include <iostream>
#include <fstream>
#include <vector>
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define MAX 100010
vector<int> G[MAX];
int viz[MAX];
void dfs(int nod){
    viz[nod] = 1;
    for(auto it : G[nod]){
        if(!viz[it]){
            dfs(it);
        }
    }
}

int main(){
    int n, m, x, y, i, s = 0;
    fin >> n >> m;
    while(m--){
        fin >> x >> y;
        G[x].push_back(y);
        G[y].push_back(x);
    }
    for(i = 1 ; i <= n ; i++){
        if(!viz[i]){
            s++;
            dfs(i);
        }
    }
    fout << s << "\n";
}