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

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

vector<vector<int>> graph(100001);
vector<bool> visited(100001, false);

void dfs(int node)
{
   visited[node] = true;
   for (auto neighbor : graph[node])
   {
      if (!visited[neighbor])
         dfs(neighbor);
   }
}

int main()
{
   int n, m, cnt = 0;
   fin >> n >> m;

   for (int i = 0; i < m; i++)
   {
      int x, y;
      fin >> x >> y;
      graph[x].push_back(y);
      graph[y].push_back(x);
   }

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