#include <cstdio>
#include <vector>

using namespace std;

int vis[100005];
vector<int> graph[100005];

void dfs(int x){
  vis[x] = 1;
  for(int i = 0; i < graph[x].size(); ++i)
    if(!vis[graph[x][i]])
      dfs(graph[x][i]);
}

int main(){
  freopen("dfs.in", "r", stdin);
  freopen("dfs.out", "w", stdout);

  int n, m;
  scanf("%d%d", &n, &m);

  for(int i = 1; i <= m; ++i){
    int x, y;
    scanf("%d%d", &x, &y);
    graph[x].push_back(y);
    graph[y].push_back(x);
  }

  int ans = 0;
  for(int i = 1; i <= n; ++i)
    if(!vis[i]){
      ++ans;
      dfs(i);
    }

  printf("%d", ans);

  return 0;
}