#include <iostream>
#include <fstream>
#include <vector>
#define pb push_back

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");

const int MAXN = 1e5;
vector<int> edges[MAXN];
int n, m, nr{0};
bool visited[MAXN];

void read() {
    int x, y;
    fin >> n >> m;
    for (int i = 0; i < m; ++i) {
        fin >> x >> y;
        edges[x].pb(y);
        edges[y].pb(x);
    }
}

void dfs(int node) {
    visited[node] = true;
    for (auto &ind: edges[node])
        if (!visited[ind])
            dfs(ind);
}

int main() {
    read();
    for (int i = 1; i <= n; ++i)
        if (!visited[i]) {
            ++nr;
            dfs(i);
        }
    fout << nr;
    return 0;
}