#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
const int NMAX = 1e5;
vector <int> g[NMAX + 5];
bool vis[NMAX + 5];
void dfs(int u) {
    vis[u] = true;
    for(int v : g[u])
        if(!vis[v])
            dfs(v);
}

int main()
{
    int n, m, u, v;
    fin >> n >> m;
    for(int i = 1; i <= m; i++) {
        fin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    int res = 0;
    for(int i = 1; i <= n; i++) if(!vis[i])
        dfs(i),
        res++;
    fout << res << "\n";
    return 0;
}