#include <cstdio>
#include <vector>
#include <bitset>

#define NMAX 100005

using namespace std;

int n,m,x,y,sol;

bitset <NMAX>ap;
vector <int>v[NMAX];

void dfs(int nod){
  ap[nod]=1;
  for (auto it:v[nod])
    if (!ap[it])dfs(it);

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

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

    for (;m;m--){
        scanf("%d %d\n",&x,&y);
        v[x].push_back(y);
        v[y].push_back(x);
    }

    for (int i=1;i<=n;i++){
        if (!ap[i]){
          dfs(i);
          sol++;
        }
    }
    printf("%d",sol);

    fclose(stdin);
    fclose(stdout);
}