#include <iostream>
#include <fstream>
#include <vector>
#define maxn 100005
using namespace std;
ifstream f("dfs.in");
ofstream g("dfs.out");
 vector<int>v[maxn];
  int i,sol,viz[maxn],m,n,x,y;
   void dfs(int x)
   {  viz[x]=1;
      for(int j=0;j<v[x].size();j++)
      if(viz[v[x][j]]==0)dfs(v[x][j]);

   }
int main()
{  f>>n>>m;
   for(i=1;i<=m;i++)
   {f>>x>>y;v[x].push_back(y);v[y].push_back(x);}
   for(i=1;i<=n;i++)
   if(viz[i]==0){dfs(i);sol++;}
   g<<sol;
}