#include <bits/stdc++.h>
using namespace std;
const int NMAX = 1e5+2;
int n,m,vis[NMAX];
vector<int> v[NMAX];

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

void dfs(int nod){
  vis[nod] = true;
  for(int fiu: v[nod]){
    if(vis[fiu] == true){
      continue;
    }
    dfs(fiu);
  }
}

int main() {
  fin >> n >> m;
  for(int i = 1; i <= m; i++){
    int x, y;
    fin >> x >> y;
    v[x].push_back(y);
    v[y].push_back(x);
  }
  int ans = 0;
  for(int i = 1; i <= n; i++){
    if(vis[i] == false){
      ans++;
      dfs(i);
    }
  }
  fout << ans;
  return 0;
}