#include <fstream>
#define NMAX 1002

using namespace std;

ifstream fin("dfs.in");
ofstream fout("dfs.out");
int n;
int A[NMAX][NMAX];
int uz[NMAX];
int nrc;

void citire();
void dfs(int x);

int main()
{int i;
 citire();
 for (i=1; i<=n; i++)
     if (!uz[i])
        {
         nrc++;
         dfs(i);
        }
 fout<<nrc<<'\n';
 return 0;
}

void citire()
{int i, x, y, m;
 fin>>n>>m;
 for (i=0; i<m; i++)
     {
      fin>>x>>y;
      A[x][0]++; A[x][A[x][0]]=y;
      A[y][0]++; A[y][A[y][0]]=x;
     }
}
void dfs(int x)
{int i;
 uz[x]=1;
 for (i=1; i<=A[x][0]; i++)
      if (!uz[A[x][i]])
          dfs(A[x][i]);
}