#include <stdio.h>
#include <vector>
#include <bitset>

using namespace std;
FILE *f,*g;

int m,n;
vector <int> graph[100002];
bitset <100002> fr;

void dfs(int nod)
{
  fr[nod]=1;
  for(int i=0;i<graph[nod].size();++i)
      if(!fr[graph[nod][i]])
        dfs(graph[nod][i]);
}
int main()
{
    f=fopen("dfs.in","r");
    g=fopen("dfs.out","w");
    fscanf(f,"%d %d",&n,&m);
    for(int i=1;i<=m;++i)
    {
        int x,y;
        fscanf(f,"%d %d",&x,&y);
        graph[x].push_back(y);
        graph[y].push_back(x);
    }
    int ss=0;
    for(int i=1;i<=n;++i)
        if(!fr[i]) ++ss,dfs(i);
    fprintf(g,"%d\n",ss);

    fclose(f);
    fclose(g);
    return 0;
}