# include <fstream>
# include <vector>
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
int n,m,i,k;
vector<int> a[100001];
bool b[100001];
void read()
{
    int x,y;
    f>>n>>m;
    for(i=1;i<=m;i++)
         {
          f>>x>>y;
          a[x].push_back(y);
          a[y].push_back(x);
         }
}
void DFS(int x)
{
    int i,n=a[x].size();
    b[x]=1;
    for(i=0;i<n;i++)
         if(!b[a[x][i]])
             DFS(a[x][i]);
}
int main()
{
    read();
    for(i=1;i<=n;i++)
        if(!b[i])
           {
            k++;
            DFS(i);
           }
    g<<k;
    f.close();
    g.close();
    return 0;
}