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

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

const int maxn = 100001;
vector<int> vecini[maxn];
bool visited[maxn];
int k, n, m;

void dfs(int nod)
{
    visited[nod] = true;
    for (int i = 0; i < vecini[nod].size(); i++)
    { if(!visited[vecini[nod][i]]) dfs(vecini[nod][i]); }
}

int main()
{
    int x, y;
    in >> n >> m;
    for (int i = 0; i < m; i++)
    {
        in >> x >> y;
        vecini[x].push_back(y);
        vecini[y].push_back(x);
    }
    for (int i = 1; i <= n; i++) if (!visited[i]) { ++k; dfs(i); }
    out << k;
    return 0;
}