#include<iostream>
#include<fstream>
#include<vector>
using namespace std;

vector<int> L[100001];
int vis[100001];
int n = 0, m = 0;

void dfs(int node) {
    vis[node] = 1;
    for (int vec : L[node]) {
        if (vis[vec] == 0) {
            dfs(vec);
        }
    }
}

int main() {
    ifstream fin("dfs.in");
    ofstream fout("dfs.out");
    fin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int a, b;
        fin >> a >> b;
        L[a].push_back(b);
        L[b].push_back(a);
    }
    
    int nr = 0;
    for (int i = 1; i <= n; i++) {
        if (vis[i] == 0) {
            nr++;
            dfs(i);
        }
    }
    
    fout << nr << "\n";
    return 0;
}