#include <bits/stdc++.h>

#define N 100005 
#define oo 0x3f3f3f3f

using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n, m;
bool viz[N];
vector<int> graf[N];

void read() {
  f>>n>>m;
  int x, y;
  for(int i = 1;i <= m;++i) {
    f>>x>>y;
    graf[x].push_back(y);
    graf[y].push_back(x);
  }
  f.close();
}

void dfs(int x) {
  viz[x] = true;
  for(const auto& vecin : graf[x]) {
    if(!viz[vecin]) {
      dfs(vecin);
    }
  }
}

void solve() {
  int result = 0;
  for(int i = 1;i <= n;++i) {
    if(!viz[i]) {
      ++result;
      dfs(i);
    }
  }
  g<<result<<" ";
  g.close();
}


int main() {
  read();
  solve();
  return 0;
}