#include<fstream>
using namespace std;

int a[100][100],n,m,viz[100],nc;

int citire()
{
    int x=1,y=1;
    fstream f;
 f.open("dfs.in",ios::in);
 f>>m>>n;
while( !f.eof() )
{
    f>>x>>y;
    a[x][y]=a[y][x]=1;

}
/*int i,j;
 for(i=1; i<=n; i++)
 {
     cout<<endl;
     for(j=1; j<=n; j++)
     {
         cout<<a[i][j]<<" ";
     }
 }
 cout<<endl;*/
f.close();
}
int dfs(int nod)
{
int i;
viz[nod]=1;
for (i=1;i<=n;i++)
if (!viz[i] && a[nod][i])
dfs(i);
}
int main()
{
    citire();
    int i;
    for (i=1;i<=n;i++)
    if (!viz[i])
    {
    nc++;
    dfs(i);
    }
    fstream g;
    g.open("dfs.out",ios::out);
    g<<nc;
    g.close();
    return 0;
}