#include <iostream>
#include <fstream>
#include <cstdlib>
#include <vector>
#include <queue>

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

#define ll long long
#define pb push_back
const int NMax = 1e5 + 5;
const int inf = 1e9 + 5;

int N,M;
bool vis[NMax];
vector<int> v[NMax];

void dfs(int);

int main() {
    in>>N>>M;
    while (M--) {
        int x,y;
        in>>x>>y;

        v[x].pb(y);
        v[y].pb(x);
    }

    int nrComp = 0;
    for (int i=1;i <= N;++i) {
        if (vis[i]) {
            continue;
        }

        ++nrComp;
        dfs(i);
    }

    out<<nrComp<<'\n';

    in.close();out.close();
    return 0;
}

void dfs(int node) {
    vis[node] = true;

    for (auto nxt : v[node]) {
        if (vis[nxt]) {
            continue;
        }

        dfs(nxt);
    }
}