#include <iostream>
#include <fstream>

using namespace std;

ifstream f("dfs.in");
ofstream g("dfs.out");

#define nmax 100006

struct graph{
   int node;
   graph *next;
};

graph *gf[nmax];
int n, m;
bool viz[nmax];

void add(int x, int y){
   graph *newNode = new graph;
   newNode -> node = y;
   newNode -> next = gf[x];
   gf[x] = newNode;
}

void citeste(){
   f >> n >> m;
   for(int i=1; i<=m; ++i){
      int x, y; f >> x >> y;
      add(x, y);
      add(y, x);
   }
}

void dfs(int nod){
   viz[nod] = 1;
   for(graph *p=gf[nod]; p != NULL; p = p->next){
      if (viz[ p->node ] == 0){
         dfs( p->node );
      }
   }
}

void rezolva(){
   int cntComp = 0;
   for(int i=1; i<=n; ++i){
      if (viz[i] == 0){
         ++cntComp;
         dfs(i);
      }
   }
   cout << cntComp << "\n";
   g << cntComp << "\n";
}

int main(){
   citeste();
   rezolva();

   f.close();
   g.close();

   return 0;
}