#include <iostream>
#include <fstream>
#include <queue>
#include <algorithm>

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

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

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

void dfs(int);

int main() {
    in>>N>>M;

    for (int i=1;i<=M;++i) {
        int x,y;
        in>>x>>y;

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

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

        ++nrComp;
        dfs(i);
    }

    out<<nrComp<<'\n';

    return 0;
}

void dfs(int nod) {
    viz[nod] = true;

    for (int k=0;k < (int)v[nod].size();++k) {
        int next = v[nod][k];
        if (viz[next]) {
            continue;
        }

        dfs(next);
    }
}