#include <fstream>
#include <vector>
using namespace std;

const int MAXN = 100010;

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

int n, m, cnt;
bool used[MAXN];
vector <int> g[MAXN];

void dfs(int nod)
{
    used[nod] = 1;
    for (vector <int> :: iterator it = g[nod].begin(); it != g[nod].end(); ++it)
    {
        if (!used[*it])
        {
            dfs(*it);
        }
    }
}

int main()
{
    fin >> n >> m;
    for (int i = 1, a, b; i <= m; ++i)
    {
        fin >> a >> b;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    for (int i = 1; i <= n; ++i)
    {
        if (!used[i])
        {
            ++cnt;
            dfs(i);
        }
    }
    fout << cnt;
    return 0;
}