#include <bits/stdc++.h>
#define NMAX 100005
using namespace std;
ifstream fin("dfs.in");
ofstream fout("dfs.out");
bool vis[NMAX];
void dfs (int x, vector<vector<int>>& g)
{
  if (vis[x]) return;
  vis[x] = 1;
  for (auto u: g[x])
  {
    dfs(u, g);
  }
}
int main()
{
  ios::sync_with_stdio(false);
  cin.tie(0);
  int n, m;
  fin >> n >> m; 
  vector<vector<int>>g(n+1);
  for (int i = 1; i <= m; ++i)
  {
    int x, y;
    fin >> x >> y;
    g[x].push_back(y);
    g[y].push_back(x);
  }
  int ans = 0;
  for (int i = 1; i <= n; ++i)
  {
    if (!vis[i]){
      dfs(i, g);
      ans++;
    }
  }
  fout << ans << '\n';

}