#include<bits/stdc++.h>
using namespace std;
ifstream in("dfs.in");
ofstream out("dfs.out");
int n,m;
vector<vector<int>>adj;
vector<int>viz;
void DFS(int nod) {
    viz[nod] = 1;
    for (int i : adj[nod])
        if (!viz[i])
            DFS(i);
}
int main() {
    in >> n >> m;
    adj.resize(n+5);
    viz.resize(n+5);
    for (int i =1; i<= m ; i++) {
        int x,y;
        in >> x >> y;
        adj[x].push_back(y);
        adj[y].push_back(x);
    }
    int cnt_comp =0;
    for (int i =1 ; i<= n ;i++) {
        if (!viz[i]) {
            cnt_comp++;
            DFS(i);
        }
    }
    out << cnt_comp;
    return 0;
}