#include<fstream>
#include<algorithm>
#include<vector>
#define dim 100002
#define pb push_back
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
vector <int> a[dim];
int viz[dim];
int n,m,sol;
void DFS(int x)
{
    int lg,i;
    viz[x]=1;
    lg=a[x].size();
    for(i=0;i<lg;i++)
     if(viz[a[x][i]]==0)
      DFS(a[x][i]);
}
void rezolvare()
{
    int i;
    for(i=1;i<=n;i++)
     if(viz[i]==0)
     {
         sol++;
         DFS(i);
     }
    g<<sol;
}
void citire()
{
    int i,x,y;
    f>>n>>m;
    for(i=1;i<=m;i++)
    {
        f>>x>>y;
        a[x].pb(y);
        a[y].pb(x);
    }
}
int main()
{
    citire();
    rezolvare();
    return 0;
}