#include <bits/stdc++.h>
#define ll long long
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n, m, rez;
bool fv[100005];
vector <int> v[100005];

void back(int nod) {
    fv[nod] = true;
    for (int i = 0; i < v[nod].size(); ++i)
        if (!fv[v[nod][i]]) {
            fv[v[nod][i]] = true;
            back(v[nod][i]);
        }
    return;
}

int main() {
    fin >> n >> m;
    while (m--) {
        int x, y;
        fin >> x >> y;
        v[x].push_back(y);
        v[y].push_back(x);
    }
    for (int i = 1; i <= n; ++i)
        if (!fv[i])
            ++rez, back(i);
    fout << rez;
    return 0;
}