#include<fstream>
# include <cstdio>
# include <vector>
# define Nmax 100002
using namespace std;
vector<long> a[Nmax];
long n,m,x,y,nr,viz[Nmax];
ifstream f("dfs.in");
ofstream g("dfs.out");

void dfs(long p)
{long q;
 viz[p]=1;
 for(long i=0; i<a[p].size(); ++i ) 
     {q=a[p][i];
      if(!viz[q]) dfs(q);
     }
}
int main()
{f>>n>>m;
 for(long i=1; i<=n; ++i ) viz[i]=0;
 for(long i=1; i<=m; ++i ) {f>>x>>y; a[x].push_back(y); a[y].push_back(x);}
 for(long i=1; i<=n; ++i ) 
     {if(!viz[i]) 
          {nr++; dfs(i);}
     }
 g<<nr<<'\n'; return 0;
}