#include <cstdio>
#include <vector>

using namespace std;
int i,n,m,x,y,nrc;
bool sel[100009];
vector<int> G[100009];


void dfs(int x)
{
   int i;

   sel[x]=true;

   for(i=0;i<G[x].size();++i)
   if(!sel[G[x][i]])

      dfs(G[x][i]);


}


int main()
{
    freopen("dfs.in","r",stdin);
    freopen("dfs.out","w",stdout);

    scanf("%d%d",&n,&m);

    for(i=1;i<=m;++i)
    {
       scanf("%d%d",&x,&y);
       G[x].push_back(y);
       G[y].push_back(x);

    }

    nrc=0;

    for(i=1;i<=n;++i)
    sel[i]=false;

    nrc=0;
    for(i=1;i<=n;++i)
    if(!sel[i])
    {
       dfs(i);
       ++nrc;
    }

    printf("%d\n",nrc);



    return 0;
}