#include <stdio.h>
#include <stdlib.h>
using namespace std;

#define NMAX 100000

#include <vector>
vector <int> g[NMAX];

int viz[NMAX+1];

int dfs(int nod){
  int i;
  viz[nod]=1;
  for(i=0;i<g[nod].size();i++){
    if(viz[g[nod][i]]==0){
      dfs(g[nod][i]);
    }
  }
}

int main()
{
  FILE *fin,*fout;
  fin=fopen("dfs.in","r");
  fout=fopen("dfs.out","w");

  int n,m,i,x,y,nr;
  fscanf(fin,"%d%d",&n,&m);
  for(i=1;i<=m;i++){
    fscanf(fin,"%d%d",&x,&y);
    g[x].push_back(y);
    g[y].push_back(x);
  }
  nr=1;
  dfs(1);
  for(i=1;i<=n;i++){
    if(viz[i]==0){
      nr++;
      dfs(i);
    }
  }
  fprintf(fout,"%d",nr);

  fclose(fin);
  fclose(fout);
  return 0;
}