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

#define NMAX 100005

using namespace std;

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

int n,m,nr,x,y;

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 (int i=1;i<=m;i++){
        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])nr++,dfs(i);

    printf("%d",nr);

    fclose(stdin);
    fclose(stdout);
}