#include <bits/stdc++.h>

using namespace std;

vector <int> graff[100001];
int parcurse[100001], nr = 0;

void dfs(int nod){
    parcurse[nod] = 1;
    for (auto x : graff[nod]){
        if (parcurse[x] == 0){
            parcurse[x] = 1;
        }
    }
}
int main() {
    ifstream f("dfs.in");
    ofstream g("dfs.out");
    int n, m;
    f >> n >> m;
    for (int i = 1; i<=m ; i++){
        int a, b;
        f >> a >>b;
        graff[a].push_back(b);
        graff[b].push_back(a);
    }
    nr = 0;
    for (int i = 1; i <= n ; i++){
        if (!parcurse[i]){
            nr ++;
            dfs(i);
        }
    }
    g <<nr;
    return 0;
}