#include <bits/stdc++.h>

using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
#define Nmax 100000
#define pb push_back

vector<int> v[Nmax];
bitset<Nmax> vis;

int n, m;

void dfs(int node)
{
    vis[node] = 1;

    for (auto i : v[node])
        if (!vis[i])
            dfs(i);
}

int main()
{
    fin >> n >> m;

    int cnt = 0;

    for (int i = 1, x, y; i <= m; ++i)
    {
        fin >> x >> y;
        v[x].pb(y);
        v[y].pb(x);
    }

    for (int i = 1; i <= n; ++i)
        if (!vis[i])
        {
            dfs(i);
            ++cnt;
        }

    fout << cnt;

    return 0;
}