#include <iostream>
#include <fstream>
using namespace std;
#define nMax 10000
ifstream fin ("dfs.in");
ofstream fout("dfs.out");
long long n,m,a[nMax][nMax],x,y,viz[nMax];
void DFS(int nod)
{
    viz[nod]=1;
    for(int i=1;i<=n;i++)
        if(!viz[i]&&a[nod][i]==1)DFS(i);
}
int main()
{
   fin>>n>>m;
   for(int i=1;i<=m;i++)
   {
       fin>>x>>y;
       a[x][y]=a[y][x]=1;
   }
   int comp=0;
   for(int i=1;i<=n;i++)
   if(!viz[i]){comp++;DFS(i);}

   fout<<comp;
}