#include <iostream>
#include <vector>
#include <fstream>

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");

vector<int> L[100001];
int vis[1000001];

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

int main() {
    int n, m;
    f >> n >> m;
    for(int i = 1; i <= m; i++) {
        int x, y;
        f >> x >> y;
        L[x].push_back(y);
        L[y].push_back(x);
    }

    int nr = 0;
    for(int i = 1; i <= n; i ++) {
        if(vis[i] == 0) {
            nr++;
            dfs(i);
        }
    }
    g << nr;
}